1" thick, for use with 175-3500 rpm machine floor scrubbers or automatic burnishers. typical applications include: black: removal of heavy build-ups of floor finish or water-based sealers without damage to the floor. black: removal of medium to heavy build-ups of floor finish without damage to the floor blue: heavy-duty scrubbing or light stripping. removes the soiled top layer of floor finish. red:spray buffing or light scrubbing. removes scuff marks and soil while producing a smooth finish. white: polishing, produces a high luster finish. natural hair: regular burnishing of floors with 1500 rpm to 2500 rpm electric machine. green: heavy-duty scrubbing to medium scrubbing.