KNS501B1/8 is a machined aluminum control knob featuring a straight knurl pattern with an arrowhead indicator positioned on the skirt for precise position indication. The knob has a black finish and is designed for use with a 1/8" shaft, with two NO. 6-32 set screws for secure mounting. Key dimensional specifications include a body diameter (A) of 0.500 inches (12.7 mm), a top diameter (B) of 0.445 inches (11.3 mm), and a skirt height (D) of 0.750 inches (19.1 mm). This knob is commonly used in electronic equipment, test instruments, and audio/visual devices where reliable tactile feedback and clear position indication are required.