High Quality Material: Pad is made of polyurethane, flexible and very durable to minimize heat transfer. Wide Application: 6.35mm shank sanding pad suitable for most kinds of rotary tools, such as die grinders, air grinders, electric drills, etc. The max operation speed is 12000rpm. Buffering pad, suitable for uneven surface polishing, protection against damage to backing pad, convenient replacement. Diameter: Pad diameter: 5\\ (125mm), shank diameter: 1/4 inch (almost 6.35mm). Buffering pad thickness: 1/2 inch (13mm). Kindly Reminder Safety concerned, it\s necessary to wear goggles or eyes protection tools in case the cleaning agents fly out while turning.