The ultimate 3 across All-in-One car seat from birth to booster (4 - 120 lb / 1.8 - 54 kg). Featuring 4 stages of complete newborn protection and all new Diono Safe+™ engineering to provide the next generation in car seat safety. From baby's first journey the radian® 3QXT provides complete newborn protection, with Safe+™ newborn travel high wedge, Safe+™ newborn protection insert, Safe+™ 2-in-1 infant positioning liner and Safe+™ newborn harness pads to provide a custom fit from birth. As your child grows the Safe+™ steel anti-rebound increases stability and reduces rebound rotation by up to 50%, so you can keep them safely rear facing for longer, up to 50 lb (approx. 4 years old). No original box