3M Fiber disc Back-Up Pad With Retainer Nut is made to drive and support fiber backed discs during sanding, grinding, or finishing processes. This essential pad is designed to fit right angle sanders equipped for TN Quick Change style attachments. The 3M fiber disc Back-Up Pad is a ribbed, one-piece construction with holes, designed for cool running of 3M fiber discs. The firm pad allows for good breakdown of various minerals, including discs using ceramic minerals, such as 3M Cubitron Products. Each pad, along with one retainer nut, is conveniently packaged in an easy open box.