Performance Machine Classic 1-Piece Steel 11.5 Rear Brake Rotor For Harley Performance Machine Classic 1 Piece Stainless Steel Brake Rotors are CNC precision machined to ensure a flat and parallel surface. The 420 stainless steel disc is hardened to meet Rc36 specifications yielding a rotor with a higher resistance to deformation. Increasing the hardness and strength of the material allows for the machining of a lightweight, 5-spoke design for improved braking performance. The braking surface features a drilled sweep pattern for optimal heat dissipation. PM brake rotors are designed for use with OEM and most aftermarket wheels and calipers. Features: CNC precision machined Lightweight 5-spoke design 420 stainless steel - material thickness: 0.200 Made in the USA