The Chicco MyFit Harness + Booster Seat is designed to grow with children from toddler through big kid, with easy transition from five-point harness to vehicle seat belt. A nine-position extended headrest and easy transition to a belt-positioning booster accommodate years of growing. The MyFit is designed with smart functionality that makes it the easiest to install simply, accurately, and securely. Every time. For reassuring protection, DuoGuard side-impact protection offers two layers of protection for two zones with a rigid shell and EPS energy-absorbing foam that surround the head and torso. The seat shell is also reinforced with a steel frame for superior impact protection.