This set of four official Fender 72 Telecaster Custom Witch Hat Style Knobs are used on their Mexico-made '72 Telecaster Custom guitars and will fit 1/4" (6.35 mm) imperial solid shaft potentiometers. They have a ridged edge to give grip and a set screw to tighten it on to control pots, the set of four has two knobs marked VOL. and two marked TONE on silver caps.