One4Life: Converts from a rear-facing infant car seat, to a forward-facing 5-point harness seat, to a high-back belt-positioning booster seat 10 Years of Use: One4Life convertible to booster car seat grows with your child from 5 ? 120 lbs and up to 63? in height Full Body Protection: 2 layers of side impact protection surround your child?s head, neck & torso Britax Safety: Patented v-shaped tether, high strength steel frame and crumple zone absorb crash energy to help keep your child safe Install Confidently: With ClickTight Installation, you?ll know it?s right in 3 easy steps Premium Comfort: Built-in arm rests, cooling channels and ventilated mesh Parent Convenience: SafeWash cover is safe to machine wash & dry and naturally flame retardant; dishwasher-safe cup holders are easy to clean Perfect Fit: 15-position headrest & harness adjust together with one hand