The Britax One4Life® Slim All-in-One Car Seat grows with your child from birth to big kid—offering 10 years of trusted safety in a space-saving 17.5" design that can fit 3-across*. With ClickTight® installation, a high-strength steel frame, SafeCell® crumple zone, and naturally flame-retardant fabrics, it delivers Britax’s highest standards of protection. Transition seamlessly from rear-facing (up to 50 lbs.) to forward-facing (65 lbs.) to high-back booster mode (120 lbs.). Cooling channels, premium padding, and an easily adjustable 15-position harness ensure comfort at every stage.
3-in-1 longevity: Rear-facing, forward-facing, and high-back booster in one seat (5–120 lbs)
Slim SpaceSaver™ design: 17.5" width fits 3-across* while keeping interior space comfortable
Extended rear-facing up to 50 lbs for added safety
ClickTight® installation ensures confident, secure installs every time
High-strength steel frame + SafeCell® crumple zone + V-shaped tether
15-position no-rethread harness and headrest adjust together with one hand
Cooling channels and premium padding for all-day comfort
Machine-washable, machine-dryable cover with no added flame-retardant chemicals
Three removable infant inserts for a better newborn fit
Built-in armrests for comfort as they grow
Easy-clean base and shell
*Britax cannot guarantee 3-across fit in all vehicles.
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