K500B1/8 is a machined aluminum control knob featuring a 3-flute design with indicator line and black finish. The knob has a nominal diameter of 0.500 inches (12.7 mm) and is designed for 1/8" shaft applications with a rotation angle of 126 degrees (3.20 mm). It includes two NO. 6-32 set screws for secure mounting and features dimensional specifications including a body diameter of 0.430 inches (10.9 mm), a flute depth of 0.374 inches (9.50 mm), and a height of 0.625 inches (15.9 mm). This knob is commonly used in industrial control panels, test equipment, and instrumentation where reliable manual adjustment and clear position indication are required.