The Full System Advantage Eliminate the guesswork of fitting washers and tools with the 3M™ Disc Back-up Pad Mounting Kit. This kit ensures a proper fit between your angle grinder and the 3M™ Disc Back-up Pad. When you combine this upgraded disc back-up pad with 3M™ Cubitron™ II Fibre Discs or select Scotch-Brite™ Abrasives, and a 3M™ Angle Grinder, you’re setting yourself up for a new level of productivity. When used together, the effectiveness of each component is enhanced to provide optimal abrasive performance — including abrasive life, cut-rate and consistency.