I finally got a good opportunity to test these Roll Locks out.I'm getting new tires for my truck, and wanted to clean up the mating/contact surfaces on the back of the wheels, the rear drums, and also the corresponding contact areas on the front rotors where the wheels mate up to them.Since I am in a winter-weather state, there was a decent bit of corrosion in the form of some rust, as well as that white corrosion that I believe is caused from a galvanic reaction between the aluminum wheels and the steel rotors and drums. I used an 18-volt drill and was able to effectively clean up all the surfaces I've mentioned. I almost made it through the entire job with just one sanding disk, but I changed it out for a second one toward the end.I will say that I was not expecting the durability that I got out of them. I was pretty tough on the them, and was working the disks at a variety of angles and speeds, and was constantly bumping against the wheel studs. There was no fraying or deterioration of the disks around the outer edges, and frankly, that surprised me quite a bit.These are handy, effective, durable, and reasonably priced for 25 disks at around $25. I have no complaints at all, and I would recommend these.