Zirconia alumina is self-sharpening and durable, allowing for a faster cut rate than aluminum oxide * Cloth backing is stiffer, tougher, and thicker than a paper or film backing * The dense placement of the abrasive grain means a higher-quality finish than an open-coat disc * Large diameter for use on stationary disc machines for dimensioning and finishing metal and wood * This disc is used with a molded rubber backing pad, sold separately