6 New Diamond Coated Sanding Drums. This is a new set of six 150 grit diamond coated sanding drums. These 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, hobby & craft, modeling, home repair, etc Each drum measures approximately 1/2" (13 mm) in diameter. We work hard to update our descriptions and pictures of our merchandise. As part of a process of ongoing innovation by our suppliers, newer versions of the item shown may be shipped before we are able to complete an update. As a result there may be a slight variation in color and design.