Premium-Grade 6pc Diamond Needle File Set Soft Grip Stone Tile Glass by Protian Excellent-quality tool set for shop, home or hobby filing, shaping, forming, material removal Blades are permanently coated with industrial diamonds to create hardest abrasive surface available Six different styles for superior versatility: half-round, round, flat, square, flat taper & triangular Comfortable soft PVC grips allow firm hold even with wet hands; 6" length, blade widths 3.0 - 5.0mm Best file for use on glass, stone, tile, hardened steel; rugged clear-view storage case Hardened tool steel blades with chrome finish for rust & corrosion resistance. Grit surface of embedded industrial diamonds, grit 100-120. Manufacturer's lifetime warranty.