This is a GN 425-8-120-CR material clamping knob manufactured by Elesa & Ganter. It is made of thermoplastic material, and features a bright, glossy finish. The knob has a flat cover and a large round head with a milled edge. The outside diameter of the head measures 120 mm, and the 8 mm internal hole is suitable for screw sizes ranging from M8 to M12. The clamping knob has an ergonomic shape, and provides a good grip. Additionally, it is resistant to substances such as oil, gasoline, cleaning agents, and weak acids.