Packing:10pcs Material:ABS Button rotation: 180 degrees Colour:black and white Size: H: 20.5mm (0.78 inch), OD: 12mm (0.47 inch), ID: 6mm (0.23 inch) Sturdy, beautiful appearance, small size, easy to install, long service life. How to use:Insert the potentiometer knob cap into the top of the potentiometer knob and gently rotate it in the direction to make sure that the knob is firm, by rotating the potentiometer knob cap, you can realise the adjustment of the sound effect. Suitable for 6mm D-shape shaft, can be used for electric guitar, bass, audio, amplifier, volume control and so on. Note: When using the potentiometer knobs, you can adjust the sound effect by rotating the cover. When using the potentiometer knob, you need to pay attention to choosing the right model and size, confirming the direction and position, operating gently and smoothly, and preventing the ingress of water and dirt.