Its only for a backup seat but at the same time i am ready to cry. He is only 4. Granted he will be 5 at the end of December. He has outgrown the radian. He is huge. He weighs 63 lbs. And is about 50 inches. Just to show how big he is. He is wearing size 7 pants, 8 tops, and a 1 shoe, at 4 He normally rides in a regent and luckily still fits in that. I have a radian as my backup seat for him that i use when my parents take him for the day. Maybe once every few months so its not alot but still i'm not ready for it. I needed room in my van so i put him in the radian and his ears were just a tad below the top of the shell. And even then i had to look closely to see. So i know he is going to outgrow it any day. I am not ready for him to be in a booster but my dad's car does not have top tether ancors so he cant use my regent or any other harnessed seat that he still fits into. And those high harnessing seats are too heavy to put in and out like that also. DD was harnessed to second grade and ds my crazy one. Luckily i have been booster training him when we drive short distances. So as long as someone is on him and watching him he should be fine. But still he is still my baby.