Black countersunk Phillips-head screws for holding a humbucker mounting ring to the guitar body, in the 13 mm (about half inch) length. That is the short size, which generally suits the low neck-position ring on a Les Paul-style guitar; the taller, slanted bridge ring usually wants the longer 17 mm screw, sold separately. Black finish to match black rings and hardware, so you are not left with one shiny nickel screw after a pickup swap. DiMarzio part GP970B.