I've owned all types of vans, including chocks, from high-end to homebuilt. Their design, as well as the durable rubber, certainly make them a stopper for motorhomes. We unhooked our van and rolled back a bit, the tire hit the chock with an impressive stop! and breathed a sigh of relief at our group. I'll be buying a few more kits for my utility and tracker aficionados. My friends, we meet own plastic. Wheel chocks that slide across the ground when the wind blows.