So my X-chocks were finally old enough to be replaced. I noticed them and thought why not try them. The FIRST time I installed one of these, here's what happened: First, as soon as the assembly started to cure, the keys that came with it bent. I'm talking about less torque than installing a spark plug (mostly by hand). The jaws of the flat, thin key (big surprise) unrolled. So I found a 1 1/8" open end wrench (luckily I had one and it's not 1" as the description says) and immediately knew I couldn't use my own wrench. You can do a little twist, but then you can't remove the wrench, so you'll have to loosen it back where you started. Turn the key and do the same. So I decided to drag the device all the way to the edge of my trailer tire to give the tool more room to rotate. I still won't work. Sure it was 12% better, but now it would take me 100% longer to install and remove them, not to mention they would now be at the very edge of my tires instead of the middle of the tread. . They appear to be well constructed (except for the wafer-thin wrench), but in actual use they fall short of the design. Now I'm looking for similar devices with a "handle" already built in.