Microfinishing Diamond discs have a tough, yet flexible film backing that provides greater durability and more consistent results. Perfect for hard materials such as carbides, tungsten, chilled iron, semi and precious stones. 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 125 micron (120 grit) discs. For use with Jooltool.