When used as a screwdriver and turning a screw, the drill chuck clamps onto the bit and holds it in place - makes sense. So far, so good. But when the screw is loosened, the cartridge opens, loosens the bit's handle, and the bit falls out. The company shows pictures of it being used as a screwdriver and advertises it as a screwdriver among other things, but it will only TIGHTEN the screws. It cannot be used to loosen screws. Useless. If you don't anticipate that you'll never get the chance to undo the bolts, then this is your tool.