I don't deny this is a well-made product at an affordable price, and it may likely work for your purposes, but the angle of the chock is designed for a really big tire given the size of the chock.  They look downright silly on my Coleman pop-up with 13" tires.  Only about the first rung and a half of the chock actually touches the tire, so the rest is left sticking out in nowhere.  I'm left thinking a simple block cut from a 2x4 will work just as well for me. Maybe an improvement to the existing design would be to make the back half gently curved down as well, rather than a straight shot. Then users would have two options, one which could fit smaller tires better.  As is, they really are over-kill on small popup campers.  Sticking with a simple block of wood works too.  I'll be returning my chocks.