The 8125-B is a control knob manufactured from black ABS plastic. It features an overall diameter of 1.25 inches, a height of 0.69 inches, and a textured top surface for improved grip. The knob is designed with a brass insert that has a bore diameter of 0.257 inches. It is secured to a shaft using a #8-32 x 5/16 inch set screw. This component is ideal for applications requiring manual control, such as on potentiometers, switches, and various electronic or mechanical equipment.