3M™ Trizact™ Cloth Belt 237AA uses proprietary microreplication technology by 3M where micron-graded aluminum oxide particles are formed into tiny pyramids of abrasive mineral and then coated on an X weight cloth backing. As these pyramids wear, fresh, sharp mineral is continually exposed to produce a consistent cut and a predictable, fine finish.|| 3M™ Trizact™ Cloth Belt 237AA uses proprietary microreplication technology by 3M where micron-graded aluminum oxide particles are formed into tiny pyramids of abrasive mineral and then coated on an X weight cloth backing. As these pyramids wear, fresh, sharp mineral is continually exposed to produce a consistent cut and a predictable, fine finish.