I bought these thinking I would use them all the time in my shop. Well , when I first used it I found that the supplied hex key didn't even fit the screw in the drill stop. Seriously, if you supply a hex key with the product make sure it fits. I found one in my own set of allen wrenches and carefully tightened the stopper. It came loose and slid over the drill during use. Note that I had about 15 repeated depth holes, all of which were inaccurate at this point. When I let go of the stopper and turned in instead Grabbing a piece of tape on the drill bit, the hex screw seemed to loosen.The steel is so soft that a gentle tightening, not even stopping the stop from moving the drill bit up, was enough to fully snug the hex bit constantly to solve. Well it's a joke. I just spent a few bucks on junk. I can't find replacement hex screws that small at the hardware store.