Microfinishing Diamond discs have a tough, yet flexible film backing that provides greater durability and more consistent results. Use to sharpen router bits, forstner bits, shaper cutters and various other tools. You can also cut and shape stones and smooth out chips. Removes heavy or fine scratches on watch crystals. The discs have peel-and-stick backs for sticking to the Ninja Cushion or Jooltool backpads. Micro-finishing film can be used wet or dry on most surface areas. Package of two 74 micron (200 coarse grit) discs. For use with Jooltool.