20 New Diamond Coated Burs. This is a new set of 20 diamond coated burs. These are 150 grit. They can be used with a Dremel tool. This master diamond bur set allows you to shape, grind and finish with precision. Great for filing glass, ceramics, tile, brick, plastics, wood, fiberglass, stone, rock carbide, gold, platinum, silver, metals or anything else that is hard. Recommended for jewelers, lapidary, hobbies and crafts, modeling, home repair, etc. Assortment includes various sizes of round, cone, inverted cone, tree, bud, cylinder and knife edge burs. Provides uniform cutting on wide a variety of materials. Use water for lubricant. All have a 1/8" (3 mm) shank.