All-in-One Car Seat: One4Life(R) Slim is a convertible and harness-2-booster seat in one! It easily converts from a rear-facing infant and toddler seat (5-50 lbs.) to a forward-facing seat (30-65 lbs.) to a high-back booster seat (40-120 lbs.) ClickTight(R) Installation: Install with confidence in 3 easy steps: pinch to open, thread and buckle, click it closed! SpaceSaver(TM) Design: Slim outside, spacious inside! The 17.5” seat is designed to fit 3 across without compromising on trusted Britax safety and premium comfort *Britax cannot guarantee 3-across installation fitment in all vehicles Premium Car Seat Cover: Features a soft knit fabric with woven mélange accents that are made from recycled polyester; the cover is safe to machine-wash and dry and naturally flame retardant with no added FR chemicals Trusted Britax Safety: Features a patented V-shaped tether, SafeCell(R) technology, a high-strength steel frame, and two layers of energy management Comfortable Rides: This slim car seat includes soft comfort pads, built-in mesh cooling channels, three infant inserts, plush padding, and a tag-free headrest Easy to Adjust: The 15-position no-rethread harness and headrest adjust together easily with one hand, and the 9-position recline has an easy-read indicator to help you find the correct angle for your vehicle Slide-Out Cup Holders: The dishwasher-safe cup holders slide out with ease for convenient cleaning and click back into place for a secure attachment during rides Accessible Color-Coded Belt Paths: Make it easy to route the seat belt through the correct path for each car seat mode Hassle-Free Cleanup: Extra space between the shell and base means you can clean under the seat with ease – and with minimal grooves in the seating area and base, you can wipe it down with no fuss