This rotary knob is made of plastic material, 6mm metal hole, built-in screw makes it can be adjustable. Potentiometer Rotary knob is useful for connecting rotary potentiometer, usually multi-turn linear potentiometer which still serves as a volume control switch. Groove handle design, more convenient switch. Plastic control knob to be assembled with a potentiometer for easier rotation. One type potentiometer volume switch, clockwise and counterclockwise rotary control. The spare part for the audio device, the 6mm shaft can be pushed easily on the 180 degree rotary knob to easily control the potentiometer. Specifications: Material: plastic, metal Color: black Suitable for shaft hole diameter: 6mm / 2.3inch Button top diameter: 27mm / 10.6in Height size: 16mm / 6.3in Rotation angle: 180 degrees Note: Light shooting 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. Package includes: 4 * Potentiometer Knob Potentiometer Switch Knob Easy to install, push-on design and with single side screw to fix, not easy to fall off. Volume control rotary knob Perfectly suitable for bass guitars with equipment electronic audio with 6 mm control shaft (round or toothed). Tone control knob for electric guitar or bass Suitable for installation on electronic equipment, or on electric guitars and basses, used to control the volume and tone of musical instruments. Strong and durable knob Made of high quality bakelite, solid and durable, aluminum design gear shape, not easy to slip and perfectly match your kitchen. Bakelite potentiometer switch knobs Visible indicator, easier to identify, easier to fine-tune mechanical equipment.