This tool has been designed to fit the three main bolts on a standard C-clamp (newer and older) used on par and leko lights. In addition to this, the slot on the handle fits most wingnuts, road case handles, Mac 500 cam thumb screws and some smaller shackle bolts. In the middle of the slot is the nut for most 6 light lamp bars. On the back of the tool is the handle slot used to get leverage on over-cranked leko and par handles. The handle slot has been made to fit most light fixtures including ETC, Strand, Altman, Thomas X handles and most old cast handles as well as mic stands with a straight handle.