Cybex Car Seat Reviews 2026: Callisto G 360 & Aton G2 Analysis

Cybex brings European design philosophy and innovative technology to the American car seat market. Known for their SensorSafe integration and unique features like 360-degree rotation, Cybex seats cater to tech-savvy parents who value cutting-edge design.

This review examines Cybex’s models and whether the engineering justifies the premium pricing, working through the published safety credentials, installation complexity, and whether the technology translates to real benefits for your family.

What Cybex sells now. Cybex’s US range has changed since this review first covered it. Its US car seat page lists nine seats: the Callisto G 360, Callisto G 360 Select and Callisto T 360 rotating all-in-ones, the Aton G2, Aton G2 Swivel, Cloud G Pro and Cloud T infant seats, and the Solution G2 and Solution T boosters. The Sirona S, Cloud Z and Aton 2 are gone. We cover the Callisto G 360 and Aton G2 first, then keep the retired seats’ sections for anyone who already owns one.

Brand Philosophy

Technology Integration

Cybex emphasizes:

• SensorSafe connectivity for child monitoring
• Innovative mechanics (rotation, lie-flat)
• European design aesthetics
• Premium material quality

The brand’s approach differs significantly from traditional American manufacturers. Where companies like Graco and Evenflo focus on affordability and straightforward functionality, Cybex targets parents who view car seats as both safety equipment and lifestyle products. This philosophy shows in sleek colorways and minimalist design lines.

Cybex emerged from the German automotive safety tradition, where engineering precision and rigorous testing standards exceed minimum regulatory requirements. The company applies this methodology to child passenger safety, often incorporating features from European car seat regulations that aren’t mandated in the United States. For example, the load leg, standard on the bases of all four of Cybex’s current infant seats, comes from European testing protocols that evaluate anti-rotation performance more stringently than FMVSS 213 requires.

Safety Approach

Cybex seats sold in the US meet FMVSS 213, the same baseline federal standard as every seat here. Cybex’s European models are also rated by ADAC (Allgemeiner Deutscher Automobil-Club), Germany’s automotive association, but those ratings apply to European versions, not the US seats.

Third-Party Evaluations:

• Consumer Reports evaluations
• IIHS (Insurance Institute for Highway Safety) booster seat ratings for older-child models

The AAP recommends rear-facing as long as possible, until children reach the seat’s rear-facing height or weight limit. Extended rear-facing capacity varies across Cybex’s range: Cybex lists 50 pounds rear-facing for the Callisto T 360 and 40 pounds for the Callisto G 360, so check the per-mode limit rather than the headline range.

Safety Statistics Context: NHTSA puts the reduction in fatal injury at 71% for infants under 1, and 54% for toddlers aged 1 to 4, in passenger cars. The AAP’s separate advice is to keep a child rear-facing until they reach the seat’s own height or weight limit. Treat the rear-facing-versus-forward-facing percentages in circulation with care: the most quoted came from a 2007 paper in Injury Prevention that the journal retracted in 2018.

Product Lineup

Callisto G 360: The Current Rotating Seat

Key Innovation: 360-degree rotation in any recline position, on an all-in-one that finishes as a booster. The Callisto G 360 is the middle of Cybex’s three rotating seats, between the Callisto G 360 Select and the Callisto T 360. It turns to face the door for loading whether it’s set rear-facing or forward-facing, and it runs three modes: rear-facing, forward-facing with the harness, and belt-positioning booster.

Limits (Cybex’s US owner’s manual):

• Rear-facing: 4-40 pounds, under 43.3 inches
• Forward-facing: 26.5-65 pounds, 33-49.2 inches, at least 1 year old
• Booster: 40-120 pounds, 44-57 inches, at least 4 years old
• Lower anchors: not above 30 pounds rear-facing or 35 pounds forward-facing; use the vehicle belt after that

Features:

• SensorSafe chest clip
• Anti-rebound base with a SecureFix360 tether, which Cybex recommends rear-facing and forward-facing
• Reinforced steel frame and Linear Side-impact Protection built into the shell
• SafeLock belt installation: tether, route the belt, click it into place
• 12-position headrest with a no-rethread harness
• Two-piece infant insert for smaller babies
• Fabrics without added fire retardant chemicals; GREENGUARD Gold certified

What to know before you buy: It rear-faces to 40 pounds, not 50, and at 35 pounds it’s heavy. Cybex calls the vehicle seat belt its preferred installation, which suits a seat whose lower anchors stop at 30 or 35 pounds. Cybex’s “37% safer” claim is footnoted as head and chest injury measures against the same seat without its safety features, not against other seats. It’s dated for 10 years from manufacture.

Price Tier: Premium

Aton G2: The Current Load-Leg Infant Seat

Key Innovation: A load leg base and SensorSafe on a 9-pound carrier. The Aton G2 is the least expensive infant seat in Cybex’s current US range. It’s rear-facing only, from 4 to 30 pounds and up to 32 inches, with the head at least an inch below the top of the seat or headrest.

Features:

• Height-adjustable load leg on the base; Cybex says it cuts crash forces on the child by up to 30% against the same seat without one
• Linear Side-Impact Protection built into the energy-absorbing shell
• SensorSafe chest clip included
• SafeLock belt tensioner on the base
• 11-position headrest with a no-rethread harness
• UPF50+ canopy
• GREENGUARD Gold certified; Cybex states compliance with the new FMVSS 213 side-impact and frontal-impact standards

Installation: The base goes in with the lower anchors or the vehicle belt, and Cybex’s manual allows the lower anchors across the whole 4 to 30 pound range. Without the base, the carrier installs with a locking lap and shoulder belt using European belt routing, the shoulder belt wrapped around the back of the shell, and Cybex certifies it for aircraft used that way.

Trade-offs: A 30 pound cap where some rivals reach 35, and a 6-year life from the date of manufacture. The Aton G2 Swivel is the same carrier on a base that turns 180 degrees.

Price Tier: Premium

Retired Cybex Seats

These three are no longer sold. The notes stay for owners and for anyone weighing a secondhand seat: check the date-of-manufacture label, stop at the expiry, and don’t use a seat whose crash history you can’t vouch for.

Sirona S 360: The Rotating Revolutionary

Availability: Cybex’s US site now marks the Sirona S “No longer available”, and Amazon lists it as currently unavailable. What follows still applies if you own one or are offered one secondhand; check the date of manufacture, because Cybex says never to use it once it’s older than 10 years.

Key Innovation: 360-degree rotation allows you to turn the seat toward the door for easiest loading and unloading. The Sirona S addresses one of parents’ most common frustrations: back strain from reaching into the vehicle to buckle children. The rotation mechanism transforms the ergonomics of car seat use, particularly for parents recovering from C-sections, those with back injuries, or anyone using compact cars with limited door openings.

Features:

• One-hand rotation operation
• Load leg for anti-rotation
• SensorSafe chest clip
• Rear-facing to 50 pounds
• Forward-facing to 65 pounds with harness
• 12-position headrest adjustment
• Linear Side-impact Protection (LSP) system
• Machine-washable fabrics
• Easy-lock bar installation system

Installation Reality: The Sirona S is not a quick-install seat. Allow extra time for the first car seat installation: the rotating base has to be positioned precisely, and the load leg must reach the vehicle floor and lock. However, once properly installed, the seat remains stable, and the rotation feature eliminates daily installation hassles.

LATCH vs. Vehicle Belt: The Sirona S supports both installation methods, and Cybex’s user guide has you extend the load leg with either, rear-facing or forward-facing. The LATCH lower anchors have their own cap, and it’s lower than a seat-plus-child calculation would suggest: Cybex says not to use them once your child weighs more than 30 pounds rear-facing or 35 pounds forward-facing. Beyond that, install with the vehicle seat belt.

Where Rotation Helps: The rotation feature shines in tight parking spots, garages with limited clearance, and vehicles with small door openings. It loses some utility in minivans and SUVs with captain’s chairs, where access is already excellent. The feature also becomes less relevant once children can buckle themselves (typically age 5-6 in forward-facing mode).

Price Tier: Premium

Cloud Z: The Lie-Flat Infant Seat

Retired. Cybex’s current US infant range is the Cloud T, the Cloud G Pro and the Aton G2, and the Cloud Z is gone from all of them. The analysis below still describes the seat accurately if you own one or you’re weighing a secondhand listing, but check the date-of-manufacture label and stop at the seat’s expiry. The Cloud T is the nearest current equivalent, though we haven’t verified that its lie-flat behaviour matches.

Key Innovation: Reclines to near-flat position on strollers for optimal newborn positioning. The Cloud Z tackles a genuine concern for newborns: maintaining airway positioning during sleep. The AAP notes that infant car seats’ semi-upright angles can affect oxygen levels in some newborns, particularly preterm infants. While car seats are safe and necessary for vehicle travel, the Cloud Z’s lie-flat feature addresses positioning concerns for stroller use, where flat positioning is safer for sleeping babies.

Features:

• Lie-flat recline on strollers (requires Cybex stroller)
• SensorSafe technology
• XXL foldaway canopy with UPF 50+ rating
• Travel system ready with multiple stroller brands (adapters required)
• Side-impact protection pods
• Removable infant insert for newborns 4-11 pounds
• European belt routing for vehicles without LATCH
• Load leg on the base

Weight Limits:

• Rear-facing: 4-35 pounds
• Height limit: 32 inches (child’s head must be 1 inch below top of seat)

The Lie-Flat Feature Explained: This feature only functions when the Cloud Z is attached to Cybex strollers via proprietary adapters. The seat cannot recline flat in vehicles; in the car it stays at the semi-reclined angle its manual requires. On compatible strollers, you can adjust the Cloud Z to nearly horizontal, creating a bassinet-like environment for newborn naps during walks or errands.

Is Lie-Flat Necessary? For most full-term, healthy infants, standard infant seat positioning is safe and appropriate. The lie-flat feature provides peace of mind for:

• Parents of preterm babies (consult your pediatrician about car seat positioning)
• Families taking extended stroller outings where baby sleeps 30+ minutes
• Parents concerned about flat-head syndrome (positional plagiocephaly)
• Those who want a stroller system that serves dual purposes (car seat and bassinet alternative)

Travel System Compatibility: The Cloud Z works with Cybex strollers natively and with numerous other brands via adapters:

• UPPAbaby Vista and Cruz (adapter required)
• Bugaboo models (adapter required)
• BabyJogger City Select (adapter required)
• Mockingbird Single Stroller (adapter required)

However, the lie-flat feature only works with Cybex Priam, Mios, Balios S, and Gazelle S strollers. Other combinations allow standard car seat clicking but not the flat recline positioning.

Price Tier: Premium

Aton 2: The Accessible Entry

Retired. The Aton 2 is gone from Cybex’s US infant range. The Aton G2 is now Cybex’s least expensive infant seat, and it includes SensorSafe.

Position: More affordable Cybex option without SensorSafe The Aton 2 represents Cybex’s answer to parents who appreciate the brand’s design aesthetic but don’t require SensorSafe connectivity or premium positioning features. It competes directly with mid-range infant car seats from Chicco (KeyFit 35) and Graco (SnugRide SnugFit 35), offering European styling at American price points.

Features:

• Lightweight at 9 pounds (among lightest infant seats available)
• XXL sun canopy with UPF 50+ protection
• European belt routing for installation flexibility
• Base sold separately
• Side-impact protection
• Energy-absorbing foam in shell construction
• 11-position height-adjustable headrest
• Linear side-impact protection system

Weight Limits:

• Rear-facing: 4-35 pounds
• Height limit: 30 inches

What You’re Not Getting: Compared to the Cloud Z, the Aton 2 lacks:

• SensorSafe technology (no smartphone connectivity)
• Lie-flat stroller positioning
• Premium fabric options (available in Cloud Q and Z lines)

What You Still Get:

• Cybex’s side-impact protection engineering
• FMVSS 213 compliance (identical safety standards)
• Lightweight portability
• European aesthetic
• Compatibility with Cybex and many third-party strollers

Best Use Cases: The Aton 2 excels for:

• Budget-conscious families entering the Cybex ecosystem
• Second vehicles where premium features aren’t necessary
• Grandparents or caregivers who need occasional infant seat access
• Parents who frequently carry the seat and prioritize low weight
• Families who plan to upgrade to Cybex convertible seats and want brand continuity

Price Tier: Mid-Range

SensorSafe Technology Explained

How It Works

SensorSafe integrates into the chest clip and connects to your smartphone via Bluetooth Low Energy (BLE) connection:

Alert Types:

• Unbuckling: Child opens chest clip while driving
• Temperature: Interior gets too hot or too cold (Cybex’s manual puts the thresholds at 95°F and 45°F)
• Left-behind: You leave vehicle with child buckled (Cybex says it can also alert emergency contacts with the car’s location)
• Duration: Child buckled for a long stretch (Cybex’s “Take a Break” notification comes after more than 2 hours)

Technical Requirements:

• A compatible smartphone with Bluetooth on
• The CYBEX mobile app (free, from the Apple App Store or Google Play)
• Whatever else the SensorSafe app guide in your box lists; the current Aton G2 and Callisto G 360 manuals point you to that guide rather than repeating it

Setup Process:

1. Download the CYBEX app
2. Pair the chest clip through the app, following the SensorSafe guide that came with the seat
3. Configure alert preferences and any emergency contacts
4. Test the alerts before the first drive

Real-World Value

While no technology replaces parental attention, SensorSafe provides backup awareness for common safety concerns. NHTSA says more than 1,000 children have died of heatstroke in hot cars over the past 25 years, 31 of them in 2025, and that over half of those deaths happen because a parent or caregiver forgot the child was in the car. SensorSafe’s left-behind alert directly addresses this tragic scenario.

Temperature Monitoring Context: NHTSA notes that a child’s body temperature rises three to five times faster than an adult’s, and that rolling the windows down or parking in the shade does little to change the temperature inside. The temperature alert is an early warning to adjust the air conditioning or remove the child.

Unbuckling Alert Value: For toddlers who master chest clip operation (typically ages 2.5-4), the unbuckling alert provides immediate notification. While children should never be left truly unattended, this feature alerts you during situations like:

• Sitting in a parking lot reviewing paperwork
• Loading groceries in an adjacent parking spot
• Quick errands where you misjudged the child’s escape artist abilities

Duration Alert Practicality: The duration alert addresses the AAP’s guidance that children shouldn’t spend excessive time in car seats outside of necessary travel. Extended car seat positioning can contribute to:

• Breathing concerns in young infants
• Positional plagiocephaly (flat-head syndrome)
• General discomfort and fussiness

Limitations and Concerns:

• Battery dependency: The chest clip battery needs replacing
• Smartphone requirement: No alerts without phone connectivity
• False positives: Extreme temperature alerts can trigger during normal seasonal changes
• Technology reliance: Some parents worry about over-dependence on technology versus vigilant parenting

Privacy and Data Considerations

The SensorSafe app handles alert history and, if you set up emergency contacts, can share your car’s location with them. Read Cybex’s privacy policy for what’s stored and where before you enable the optional features.

Comparison: Cybex vs. Competitors

Feature	Callisto G 360	Nuna RAVA	Britax Boulevard	Graco 4Ever
Rotation	360°	None	None	None
Technology	SensorSafe	None	None	None
Rear-Facing	40 lbs	50 lbs	40 lbs	40 lbs
Forward-Facing Harness	65 lbs	65 lbs	65 lbs	65 lbs
Booster Mode	Yes (120 lbs)	No	No	Yes (120 lbs)
Installation	SafeLock belt or LATCH, plus tether	LATCH/Belt	ClickTight	LATCH/Belt
Price Tier	High-End	Premium	Mid-Range	Mid-Range
Fabric Quality	Premium	Premium	Standard	Basic
Lifespan	10 years	10 years	10 years	10 years

Detailed Competitive Analysis:

Cybex Callisto G 360 vs. Nuna RAVA: Both are premium convertibles. The RAVA rear-faces to 50 pounds, ten more than the Callisto G 360, and has no rotation mechanism to learn. The Callisto counters with rotation, SensorSafe and a booster mode the RAVA lacks. If extended rear-facing is the priority, the RAVA or Cybex’s own Callisto T 360 is the better fit; if loading ergonomics matter more, the Callisto earns its premium.

Cybex Callisto G 360 vs. Britax Boulevard: The Boulevard is a traditional American design: ClickTight installation, SafeCell impact protection, and no rotation or app. Both stop rear-facing at 40 pounds. The Boulevard costs considerably less and suits families who see a car seat purely as safety equipment; the Callisto adds rotation, SensorSafe and a booster stage.

Cybex Callisto G 360 vs. Graco 4Ever: Both run from birth to a 120 pound booster and both rear-face to 40 pounds, so the gap is features and price. The Callisto rotates, carries SensorSafe and uses an anti-rebound base and tether; the 4Ever costs much less. This one comes down to how much you’d pay for rotation in your car.

Installation Deep Dive

Installing the Callisto G 360

Cybex’s own summary of the SafeLock install is tether, route, click: fasten the tether to the vehicle’s anchor, route the seat belt through the belt guide, click it into place and close the SafeLock door. Cybex recommends the tether in both directions, and because the install covers rear-facing and forward-facing, you don’t redo it at the turnaround. You can use the lower anchors instead, but only up to 30 pounds rear-facing and 35 pounds forward-facing, and never together with the seat belt. Before driving, the seat must be locked rear-facing or forward-facing, never left in the sideways loading position, even when empty.

LATCH Installation Process (Sirona S, for existing owners)

Step-by-Step:

1. Position base: Place rotating base in vehicle seat, ensuring load leg area has floor contact point
2. Extend load leg: Adjust load leg to contact vehicle floor (color indicator shows proper tension)
3. Locate LATCH anchors: Find lower anchors in vehicle seat bight (crease between seat back and cushion)
4. Attach connectors: Click LATCH connectors to anchors, listening for audible click
5. Tighten straps: Pull LATCH strap to remove slack, pressing base firmly into vehicle seat
6. Lock mechanism: Engage lock bar to prevent rotation during travel
7. Check installation: Base should move less than 1 inch side-to-side or front-to-back at belt path
8. Install seat: Click seat onto base (simpler than base installation)
9. Test rotation: Verify rotation operates smoothly and lock engages properly

Common Installation Mistakes:

• Incorrect load leg angle: Must contact floor perpendicular, not at steep angle
• Insufficient LATCH tension: Most installations are too loose; proper installation requires significant force
• Recline angle errors: Rear-facing requires more recline; indicators show proper positioning
• Rotation lock failure: Lock must engage before driving; test by attempting to rotate while locked

Vehicle Belt Installation (Sirona S)

Cybex’s guide requires a seat belt installation once your child is over 30 pounds rear-facing or 35 pounds forward-facing:

1. Remove LATCH connectors: Detach from vehicle anchors
2. Thread belt: Route vehicle seat belt through belt path on base
3. Secure buckle: Click vehicle belt buckle
4. Lock belt: Most modern vehicles have locking mechanisms; pull belt fully out and let it retract to engage
5. Remove slack: Push down on base while pulling belt tight
6. Verify lock: Attempt to pull belt out - should be locked in place
7. Test tightness: Same 1-inch movement rule applies

Note: Keep the load leg extended with a seat belt installation too. Cybex’s belt-install steps include extending it, and its guide calls the load leg strongly recommended.

Who Should Buy Cybex?

Choose Cybex If:

• You value cutting-edge technology
• The rotation feature appeals to you (the Callisto 360 seats) due to back issues, small vehicles, or ergonomic preferences
• You want European design aesthetics and premium material quality
• Budget allows for premium pricing
• SensorSafe connectivity provides meaningful peace of mind for your parenting style
• You’re building a Cybex ecosystem (stroller + car seat compatibility)
• Extended rear-facing matters for your larger toddler (Cybex lists 50 pounds rear-facing for the Callisto T 360)

Consider Alternatives If:

• You prefer simpler, proven designs without learning curves
• You don’t need rotation and want the simplest install (a belt-tensioning system like Britax ClickTight does the same job without a rotating shell)
• You want better value proposition (Chicco NextFit offers similar features at a lower price)
• You don’t need technology features and view them as potential failure points
• You’re buying for grandparents or caregivers who may struggle with complex systems
• You need booster mode extension (Graco 4Ever, Britax Frontier) - see our car seat types guide to understand the differences

Middle-Ground Compromise Options

If you like Cybex’s European aesthetic but not the price:

• Nuna PIPA Lite: Lighter weight infant seat at a lower price with similar design language
• Maxi-Cosi Magellan: Extended-use convertible at a mid-range price with European heritage
• Chicco Fit2: A rear-facing-only infant and toddler seat at a mid-range price

If you like rotation but not Cybex’s complexity:

• Evenflo Revolve360: 360-degree rotation at a lower price (the Gold versions add SensorSafe)
• Graco Turn2Me: Budget rotation option at a lower price (fewer features; check NHTSA’s recall lookup for your model before buying)

If you like SensorSafe technology: Evenflo sells SensorSafe on its Gold line in the US. Many newer vehicles also offer built-in rear seat reminder systems; check your vehicle’s features.

Maintenance and Longevity

Care Instructions

Fabric Maintenance:

• Remove covers for machine washing (gentle cycle, cold water)
• Air dry to prevent shrinkage and elastic degradation
• Spot clean between washes using mild soap and water
• Avoid harsh chemicals, bleach, or fabric softeners (can degrade flame-retardant treatments)
• Wash covers every 2-3 months or immediately after spills/accidents
• Check manufacturer labels before washing - some Cybex premium fabrics require hand-washing

Plastic and Harness:

• Wipe shell with damp cloth and mild soap
• Avoid abrasive cleaners
• Check harness for fraying regularly (replace if any fraying observed - harnesses available through Cybex customer service)
• Never submerge harness straps in water (can degrade webbing strength)
• Store indoors away from extreme temperatures
• Never lubricate the buckle; follow the manual’s cleaning instructions for it

SensorSafe Chest Clip Care:

• Wipe with damp cloth only
• Do not submerge in water (contains electronics)
• Replace the battery when the app says it’s low
• Check battery indicator in app monthly
• Store extra batteries away from children (button batteries are choking hazards)

Long-Term Value

10-Year Consideration: Cybex convertible seats offer 8-10 year lifespans, making them suitable for multiple children when purchased new and properly maintained. A Callisto G 360 made in 2026 expires in 2036, potentially serving more than one child from birth to booster age. However, this long-term value only applies if:

• You have multiple children within the 10-year window
• The seat hasn’t been in any crashes (even minor accidents require replacement per manufacturer guidance)
• You maintain the seat properly (regular cleaning, indoor storage, harness checks)
• You can properly install it in future vehicles (rotation bases may not fit all car models)

Cost-Per-Year Analysis:

• Callisto G 360: Premium-priced, spread over a 10-year lifespan from birth to booster
• Aton G2: Premium-priced for an infant seat, over a 6-year lifespan

Compare to budget options:

• Graco SnugRide Lite LX: Budget-priced infant seat, over a 7-year lifespan

The value proposition depends on whether Cybex’s features (rotation, SensorSafe, extended rear-facing) provide sufficient benefit to justify the cost difference.

Resale: Expired seats should never be sold, and a used seat’s remaining years before expiry matter more than its brand.

Important safety note: NHTSA and the AAP strongly discourage buying used car seats from unknown sources. You cannot verify:

• Crash history (even minor accidents compromise structural integrity)
• Proper storage conditions (extreme temperatures degrade materials)
• Complete parts (missing pieces affect safety)
• Expiration dates (some sellers remove or obscure expiration labels)

Resale is only appropriate when you know the seat’s complete history - typically selling between your own children or to trusted family members.

Warranty and Support

Coverage: Check Cybex’s current warranty terms and register the seat. Retailer return policies vary, so check them before you buy.

What’s Covered:

• Manufacturing defects, within the warranty’s terms

What’s Not Covered:

• Damage from crashes (car seats are one-use crash items - must be replaced)
• Normal wear and tear (fading, minor pilling, odor absorption)
• Improper installation damage
• Modifications or unauthorized repairs
• Damage from improper cleaning (bleach damage, excessive heat)

Customer Service: Cybex’s US site lists its current customer service contact options for installation questions and replacement parts.

Replacement Parts Availability: Cybex provides replacement parts through customer service:

• Harness straps: Available through customer service
• Chest clip (non-SensorSafe): Available through customer service
• SensorSafe chest clip: Available through customer service
• Seat covers: Available through customer service (varies by model)
• LATCH connectors: Available through customer service
• Infant inserts: Available through customer service

For a frayed harness or faulty buckle, stop using the seat until the part is replaced.

Further Reading

• Best Car Seats for Special Needs Children: Roosevelt, Carrot & More
• Maxi-Cosi Mico Review: Lightest Premium Infant Car Seat
• Best Convertible Car Seats of 2026

Advanced Safety Features Breakdown

Linear Side-Impact Protection (L.S.P.)

L.S.P. is Cybex’s name for side-impact protection that reduces crash forces on the child when a door leaves little crush space. How you use it depends on the seat.

Current seats: On the Aton G2 and Callisto G 360, Cybex builds L.S.P. into the energy-absorbing shell, so there’s nothing to deploy. Cybex’s FAQ describes seats where the protection sits in the shell or fixed side wings as working without any action from you.

Seats with a deployable L.S.P. (the Sirona S had one):

• Extend it on the side of the seat closest to the vehicle door
• Never extend it toward the centre of the car, another passenger or another car seat
• Don’t use it when the seat is in the middle seating position
• Swap sides if you move the seat to the other side of the vehicle

Load Leg and Anti-Rebound

The load leg on the Aton G2 base, and on the retired Sirona S, extends to the vehicle floor and limits the seat’s forward rotation in a frontal crash. The Callisto G 360 takes the other route: an anti-rebound base and a SecureFix360 tether, which Cybex recommends using rear-facing and forward-facing.

Load Leg vs. Anti-Rebound:

• Load leg (Aton G2 base): Extends to the vehicle floor, limiting forward rotation
• Anti-rebound base or bar (Callisto G 360, and many other brands’ infant seats): Braces against the vehicle seat back, limiting rebound after impact

Both systems accomplish similar goals through different mechanisms. For load legs, Consumer Reports’ crash tests found about 46% lower average head-injury risk in infant seats that have one.

Energy-Absorbing Materials

Energy-absorbing foam lines the shell to slow the child’s deceleration in a crash. Check each model’s listing for the foam type Cybex uses, because it varies by seat.

Our Top Picks

Our Top Pick

#1

Cybex Callisto G 360 Rotating All-in-One Car Seat

Best rotating Cybex seat

C

Cybex Callisto G 360 Rotating All-in-One Car Seat

+1

4.5

4.5

Check Price →

The middle of Cybex's three current rotating seats, between the Callisto G 360 Select and the Callisto T 360. Against the retired Sirona S it swaps the load leg for an anti-rebound base and a tether, adds a booster mode, and keeps SensorSafe. The catch is the 40 lb rear-facing limit and the low lower-anchor limits, which make the seat belt the install you'll end up using.

View on Amazon

What We Like

• 360-degree rotation in any recline position, so the seat turns to face the door for loading, rear-facing or forward-facing
• SafeLock one-time belt installation with a SecureFix360 tether that Cybex recommends in both rear-facing and forward-facing modes
• Three modes, rear-facing, forward-facing harness and belt-positioning booster, with a 10-year lifespan
• SensorSafe chest clip alerts for unbuckling, long stretches in the seat, temperature and a child left behind
• Anti-rebound base, reinforced steel frame and Linear Side-impact Protection
• Fabrics free of added fire retardant chemicals; GREENGUARD Gold certified

What We Don't

• Rear-facing stops at 40 lbs, below the 50 lb cap on some rotating all-in-ones
• Lower anchors stop at 30 lbs rear-facing and 35 lbs forward-facing, well below the harness limits, so most families will move to a seat belt install
• Heavy at 35 lbs, so it is a seat you install once
• Flagship pricing, near the top of the rotating seat tier

Runner-Up

#2

Cybex Aton G2 with Load Leg Base

Best Cybex infant seat

C

Cybex Aton G2 with Load Leg Base

+3

4.5

4.5

Check Price →

Cybex's current load-leg infant seat and the replacement for the Aton 2 in its US range. The Load Leg base, L.S.P. and a SensorSafe chest clip come standard on a 9 lb carrier, and the lower anchors are usable across the whole 4-30 lb range. The trade-off is a 30 lb cap where some rivals reach 35.

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What We Like

• Load Leg base reduces crash forces on the child by up to 30%, Cybex says, against the same seat without it
• Linear Side-Impact Protection (L.S.P.) built into the energy-absorbing shell
• Light 9 lb carrier, with European belt routing for a baseless install
• SensorSafe Smart Technology integrated into the chest clip, alerts for unbuckling and child-left-behind
• 11-position no-rethread harness with adjustable headrest
• Meets the new FMVSS 213 side impact and frontal impact standards, Cybex says; GREENGUARD Gold certified for low chemical emissions

What We Don't

• 30 lb rear-facing weight cap trails 35 lb competitors
• No anti-rebound bar on the base; the manual's anti-rebound option is a carry-handle position
• Premium pricing without a rotating base (the Aton G2 Swivel adds a 180-degree base)
• Rear-facing only, and outgrown at 30 lbs or 32 inches

Best Value

#3

Cybex Sirona S

Retired, for existing owners

C

Cybex Sirona S

4.5

4.5

No longer available

Premium seat with load leg and innovative rotation.

No longer available

What We Like

• Load leg, used rear-facing and forward-facing, reduces rotation and absorbs crash energy
• 360-degree one-hand rotation for easier loading
• SensorSafe chest clip with smartphone alerts
• Linear Side-impact Protection
• 12-position recline

What We Don't

• No longer available from Cybex or Amazon
• Lower anchors stop at 30 lbs rear-facing and 35 lbs forward-facing; seat belt install after that
• Heavy at 30.4 lbs, which makes moving it between vehicles difficult
• Requires a smartphone for SensorSafe alerts
• No booster mode

#4

Cybex Cloud Z

Retired, for existing owners

C

Cybex Cloud Z

+4

4.5

4.5

No longer available

Premium infant seat with innovative lie-flat feature.

No longer available

What We Like

• Near-flat reclining position for use outside vehicle
• SensorSafe technology alerts for critical safety situations
• XXL foldaway sun canopy with UPF 50+
• Compatible with multiple stroller travel systems

What We Don't

• Premium price point for infant-only seat
• Base is heavy at 11 lbs making transfers less convenient

#5

Cybex Aton 2

Retired, for existing owners

C

Cybex Aton 2

+3

4.5

4.5

No longer available

Excellent safety features at moderate premium price.

No longer available

What We Like

• Load leg included for enhanced stability
• Linear Side-Impact Protection (LSP) system
• Lightweight carrier at about 9 lbs without base

What We Don't

• Premium pricing compared to basic infant seats
• Base with load leg takes up more vehicle space

Sources & Research

• CYBEX US, Callisto G 360 (official product page, specifications, dimensions and FAQ)
• CYBEX Callisto G 360 US owner's manual (linked from Cybex's download center, US version from 2025-03-01)
• CYBEX US car seat range (lists Callisto G 360 among 9 current seats)
• Cybex Online US Official Product Page
• CYBEX Aton G2 US owner's manual (linked from Cybex's download center, US version from 2025-04-01)
• Strolleria New Product Spotlight
• Bambi Baby Product Comparison
• CYBEX US, Sirona S with SensorSafe (official product page, marked no longer available)
• CYBEX Sirona S US user guide (linked from Cybex's product page)
• Cybex US Infant Car Seats collection (Cloud Z absent)
• CYBEX Aton 2 US product page (Wayback Machine, August 2019)
• CYBEX Aton 2 US product information (Wayback Machine, May 2022)