SuperGrindz Heavy Duty Brake Hub Cleaning Discs are designed to remove rust and corrosion from brake hubs. The disc features Aluminum Oxide mineral in a non-woven nylon web that was reengineered for high conformability, high strength and low chunking. 6-Pack replacement pads. The SuperGrindz brake hub cleaning discs are designed specifically for removing all rust and debris from all wheel-end mating surfaces. It is designed to clean around a wheel stud, the hub, brake drum and wheel mating faces. Important to note, the disc is not designed to clean the threads of the wheel stud itself, but everything else around it. When mounted on the holder, the center hole on the disc allows the operator to slide over and round the the wheel studs to effectively clean the surface around the wheel stud, all without damaging the wheel stud threads. To ensure the proper torque is achieved, it is necessary to clean all threaded and mating surfaces of a wheel-end thoroughly to ensure proper clamping force is achieved, in-turn providing the proper torque. Designed for use with Automotive, SUV, Light Truck, Utility Trailer, UTV and ATV applications. NOTE: For best performance, operate at low speeds below 10,000 RPM, and in forward (clockwise) direction only.