3X Hook & Loop Sanding Discs cut faster, last longer and remain cool! Created with a blend of ceramic alumina and heat-treated aluminum oxide grain, bonded with a resin fiber reinforced backing and coated with an anti-clogging agent. A patented universal hole pattern allows them to be used on any 5" random orbital sander. The discs last longer due to the resin bonding that secures the abrasive to the fiber reinforced backing along with an anti-clog coating.