Contains 6 Purple 6000 Grit abrasive belts for the Knife & Tool Sharpener Mk.2. Work Sharp belts are not just sandpaper. Work Sharp Abrasive belts are formulated, designed, and made for precision sharpening of high-strength steels. The grit symmetry, spacing, and backing flexibility are all designed to produce the optimal convex edge with minimal heating or material takeoff. If you’ve ever used a belt sander to sharpen, you know hot quickly the steel heats and how much excess material can be removed if you aren’t careful. Our abrasives are a key component of our success in the sharpening world.