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, switch more convenient. 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 The color: black Suitable for shaft hole diameter: 6mm / 2.3inch Button top diameter: 27mm / 10.6inch Height size: 16 mm / 6.3 inch Angle of rotation: 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 error allowed is +/- 1 to 3 cm.