3M Roloc coated 361F quick change disc uses aluminum oxide as the abrasive material and has a diameter of 3 in. 3M incorporates this aluminum oxide material into the quick change disc forming a grit of P120. This abrasive is on a cloth backing, XF weight. All abrasive products that rotate or spin, such as the ones in this category, have a maximum speed at which you can run them. This 3M quick change disc can be run at a maximum speed of 20000 RPMs.