3M coated 769F Type 29 flap disc uses aluminum oxide/ceramic psg as the abrasive material and has a diameter of 5 in. 3M incorporates this aluminum oxide/ceramic psg material into the flap disc forming a grit of 80+. The quick change attachment allows for easy mounting to the tool or pad. 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 flap disc can be run at a maximum speed of 12000 RPMs. The 3M flap disc uses plastic for the backing plate.