These discs are made of gold a durable product very well suited for sanding at high speeds. Gold is an all-round sanding material that can be used for many purposes. In order to achieve an optimal sanding result, the semi-open grit binding and special stearate coating are designed to prevent clogging and pill forming. Features: * B weight backing giving better edge wear and overall wearability * The Stearate aluminum oxide grit provides a fast, uniform cut * Discs can also be used with a standard pad without punched holes * High strength resin bond * Adhesive backing What"s In The Box: * Mirka 23321150 5-Inch 5-Hole 150-Grit Dustless PSA Sanding Discs - 100-Pack