This is NOT a very well made bit holder. The wire clamp intended to hold the bit is flimsy at best. I used a bit holder in a 1/4 hex slot and the wire holder eventually gave up. I needed this bit holder to drive screws into the soundboard with an impact wrench. I ended up using epoxy and glued the bit holder onto the hex head and it worked. After that I ordered a Milwaukee unit and it is MUCH better made. This is not up to usual Dewalt standards.