The Greco Nautilus 65 LX 3-in-1 harness booster car seat spans from toddler to youth, to help keep your growing child safe. Featuring True Shield advance side impact protection from head to hips, this seat grows with your child from 22-120lb. It starts as a harness booster seat from 22-65 lb., converts to a high back booster from 40-100 lb., and becomes a backless booster seat from 40-120 lb. The Simply Safe Adjust harness allows you to adjust the harness and headrest together as your child grows through each mode, and then the harness stores away easily in booster mode. You’ll appreciate the ease of the fuss-free harness, for easy in and out, and the belt lock off, for easy installation. Little passengers will enjoy the premium fabric, body support, personal cup holder and storage compartment. The perfect blend of safety, function, and comfort. Excludes backless mode