The Chicco KeyFit Strada Booster has triple zone side-impact protection. Headrest and side wings adjust UP and OUT for maximum protection of head, shoulder, and lumbar zones. For children 4-10 years old, 38"-57" tall and 33-100 lbs. Converts to a backless booster for children 40-100 lbs. More energy-absorbing EPS foam than most other seats. Deluxe padded seat with micro-vented upholstery for breathable comfort. Adjustable, clip-on cup holder.