Resin bonded aluminum oxide abrasive is coated on a durable Xwt backing to provide maximum life Free cutting and clog resistant open coating makes cloth discs ideal for heavy stock removal Hook & Loop discs can be used on portable random orbital sanders Norton cloth sanding discs are made with aluminum oxide abrasive for long life The heavy, X-weight cotton backing makes them durable Tired of buying cheap sandpaper that clogs or doesn't last? If so, now you can afford to step up to Norton professional quality abrasives. All disks feature patented, ceramic alumina abrasive and a unique, fiber reinforced backing. The 3X high performance disks fit 5 and 8 hole sanders, last 3 times longer than conventional aluminum oxide disks, are edge tear resistant, and provide a consistent finish.