MIJ Hut/UFO/Bell Knob Printed Numbering Set 4pc +Toggle Knob Inch Amber Brand New Made-In-Japan Traditional UFO Knobs for Inch and Toggle Switch Knob for Inch Replacement control knobs These knobs are for inch size POT (for ex.CTS ) If your guitar's POT is mm size (for ex. Japanese,Chinese,Korean ), please choose same one for metric. Toggle Knob inner diameter: 4mm