(1) Single guitar top hat control knob chrome with abalone insert fits CTS pots (KN-00011) (1) Single guitar top hat control knob chrome with abalone insert. Fits solid shaft USA 6.35mm CTS pots. Bottom Diameter = 24.9mm (0.98 inch). Height = 15.2mm. Attached with a Hex screw (allen key) on the potentiometer. Brand new.