3M Green Corps Hookit Abrasive Disc 255U combines features for smooth, even sanding on tough surfaces. Grade 36-100 ceramic and aluminum oxide blend abrasive is resin bonded to durable E weight paper backing, with open coat construction that reduces loading even on fresh filler. These discs are ideal for shaping plastic filler and putty, paint removal and scratch refinement on bare metal. Resin bonded for heat resistance. Superior Dust Resistance. Sold by box of 25.