Electronic control potentiometer knob for 6 mm diameter D-axis, volume control knob, audio knob, guitar knob, electric guitar knob, encoder encoder switch knob Suitable for shaft hole diameter: 6mm/0.24-inch The replacement part of audio equipment, the 6mm D-shaft can be easily pushed in. The potentiometer rotary knob is used to connect a rotary potentiometer, usually a multi-turn linear potentiometer, which is always used as a volume control switch. Material:plastic colour:Black + White Package Contents: 20 x Potentiometer Rotary Knob Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.