I bought my first camper in April 2018 and soon came across it. But with all the other first time purchases I've put them aside for now. Also, I already had several different wheel chocks, so I wasn't concerned about safety. Then, as I was getting the camper ready for the first ride of the year, I noticed that it rocked more inside with my dogs. these are no longer puppies! So I decided to try them and went ahead and got them. and I'm using it on my first outing right now. To be honest, I'm not happy with them. I still notice camper movements but I'll admit it's less than without them so yeah I'm happy with them. And I would say no matter how passionate I am about buying things for our camper, I would always buy them again. I don't think they are a necessity however, but if you have a little extra cash for something for your camper this is something worth spending that money on. In terms of their use, our tires are spaced 8.5 (as close as possible between them) and there is still some room for the frogs to open. I'd also like to add that it's good that they include a small ratchet wrench to open/close the brake pads, but I've found it's best to adjust them so they barely slide between the tires, and then between them to push and tighten the tires. high. If I take them out I think I'll loosen them just enough to pull them out and then store them that way. In general, they are easy to use, but when setting up a camp, this is still an additional task, but for me this is not a problem. I would still buy them again. 4 stars instead of 5 because they don't remove all moves.