Both are infant car seats — here are their published manufacturer specs side by side.
This compares published manufacturer specs — not safety or fit advice. The seat's manual, your vehicle's manual, NHTSA's tools and a certified CPST are the fit-and-safety authority; always check them before installing.
As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. Weight ranges are the manufacturer's published limits across all modes.
How they differ
the Cybex Aton 2 is listed narrow (roughly ≤17″) for fitting three across a back seat; the Nuna PIPA RX isn't listed narrow
Published limits
Mode
Nuna PIPA RX
Cybex Aton 2
Rear-facing
4–30 lb · 16–30 in
4–35 lb
Useful life
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Nuna PIPA RX: Rear-facing-only infant carrier: for children 4–30 lb and 16–30″. Useful life is set by the label on the base/child restraint (no printed number of years in the manual, unlike Nuna's convertible RAVA which prints 10 years).
Cybex Aton 2: Rear-facing-only infant carrier: for children 4–35 lb and 30″ or less (no minimum height printed, unlike the newer Aton G). Useful life is set by the printed "Expires On" date (no printed number of years in the manual).
That is the record of the brand — not a verdict on these models. A recall names specific models and manufacture-date ranges, and a seat missing from the record is not "recall-free": check nhtsa.gov/recalls with the model and date of manufacture on your seat's label. Source: NHTSA, retrieved 2026-09-05.
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FAQ
What's the difference between the Nuna PIPA RX and the Cybex Aton 2? The Nuna PIPA RX is FAA-approved for aircraft, lightweight/travel; the Cybex Aton 2 is narrow for 3-across, FAA-approved for aircraft, lightweight/travel. Both are infant car seats.
Which fits three across, the Nuna PIPA RX or the Cybex Aton 2? The Cybex Aton 2 is listed narrow (~≤17″) for 3-across; the Nuna PIPA RX isn't. Three-across fit still depends on your exact vehicle — confirm before buying.
Which is right for my car and child, the Nuna PIPA RX or the Cybex Aton 2? That depends on your specific vehicle and child — this page compares published manufacturer specs only, not fit or safety. Check the seat manual, your vehicle manual, NHTSA's car-seat finder and ideally a certified CPST before deciding.
Citing these specs? Go ahead — published manufacturer data, last verified 2026-06-11. Copy a ready-made reference: