Material: Outer part: Plastic PA 12 G, white (natural color) with steel core. Milled, straight teeth. Tooth quality 8e25 DIN 3967. Temperature range -60°C to +120°C, short periods 150°C. - Special plastic with excellent material properties. - Enables snugly fitting, high strength shaft-hub connection. - Optimal force transmission due to cylindrical contact area. - Light, silent and clean, with excellent dry running properties.