Finally, the car seat that parents have been searching for is here. Our Nautilus? 3-in-1 car seat helps keep your child secure in a 5-point harness, from 20-65 lbs. When she?s ready, it converts to a belt-positioning booster from 30-100 lbs. And as she continues to grow, the Nautilus grows with her, transitioning into either a Highback or Backless booster for a comfortable fit up to 100 lbs. Extensively crash tested, including side-impact testing, outfitted with reinforced steel and thoughtfully designed with plush comfort features, this 3-in-1 car seat is will last your little travel companion well into childhood.