The Graco Baby Nautilus 3 in 1 Carseat - Gavit helps keep your child secure from 20 to 100 lbs. The Nautilus converts from a harnessed booster to a high back belt-positioning booster and finally to a backless belt positioning booster. The harness booster can be used up to 65lbs, and as your little one continues to grow, the Nautilus does too, transitioning into a Highback belt positioning booster which can be used from 30 Ð 100lbs, and finally into a Backless belt positioning booster for a comfortable fit from 40 to 100 lbs. The seat is designed to help keep your child in a harness booster longer as well as to fit them up to 57" tall. This seat is extensively crash tested to meet or exceed U.S safety standards, side-impact testing, and outfitted with reinforced steel for effective energy management. Nautilus has been thoughtfully designed with plush comfort features, an integrated cup holder and storage compartments, as well as a one-hand height adjustable headrest to help keep your growing child happy on even the longest rides! This 3-in-1 car seat is will last your little travel companion well into childhood.