I recently bought some decorative hinges and handles for garage doors. They were bolted together, and anyone who has ever drilled or tried to center a drill in a hole hasn't made it dance and doesn't end up in the middle. Or use a center punch and still not hit dead center? Then if you miss, the screw will either never sit flush or the item will move and then it won't be where you wanted it to be. It eliminates all of that. Find the right size and every hole will be in place. I had no problems other than one of the bits coming loose, but they provided an Allen wrench to adjust and replace the bits. I'm sure there is better overall quality out there, but on rare occasions I need to center something perfect. I assumed I was wondering how long they would last if I hung slings etc all day because I believe everything has to be paid for. If cheaper, then in general the corners were cut off somewhere. So if you use it from time to time you can't go wrong.