2 Diamond Coated Sanding Drums Jewelers Lapidary 1/2" These are a new set of diamond coated sanding drums They are great for filing glass, ceramics, tile, brick, plastics, wood, fiberglass, stone, rock carbide, gold, platinum, silver, metals or anything else that is hard Longevity is assured as the diamond particles are electroplated onto the surface of the metal Recommended for jewelers, lapidary, hobbies, crafts, modeling, home repair, etc Can be used with a rotary tool