It often happens that you need to drill a hole in something, but in such a way that you don't punch it through, i.e. there should be no traces of drilling on the back side of the material. Someone applies duct tape to obtain the desired result, winding it on the drill, and someone goes a more competent and professional way, using specialized stoppers. They are washers made of high-carbon steel, which are put on the drill bit in the necessary place. Thus, after reaching a certain depth, the drill bit rests on the washer and does not go any further. The delivery set includes 8 washers for drill bits from 3 to 16 mm and a hexagonal wrench for fixing them.