3M Trizact cloth belt 307EA uses our proprietary microreplication technology where micron-graded aluminum oxide particles are formed into tiny pyramids of abrasive mineral and then coated on a rayon backing. As these pyramids wear, fresh, sharp mineral is continually exposed to produce a consistent cut and a predictable, fine finish. - Self-sharpening pyramids start sharp, stay sharp and run cooler than conventional abrasives. Flexible backing flows over contoured surfaces for consistent finishing.