Features 1、Diamond rotary grinding set with rougher surface, which are quicker than the larger grit burrs when sanding, polishing and engraving. 2、Suitable for stone, , metal, hardwood, tile, ceramics, marble, granite and other hard materials. 3、10 different grinding drill bits(total 20pcs) for abrasive, engraving, cutting, polishing, carving and etching. Specification Features: Diamond rotary grinding set with rougher surface, which are quicker than the larger grit burrs when sanding, polishing and engraving. Suitable for stone, , metal, hardwood, tile, ceramics, marble, granite and other hard materials. 10 different grinding drill bits(total 20pcs) for abrasive, engraving, cutting, polishing, carving and etching. Grinding drill bits with universal 3mm (1/8 inch) shank, fits most rotary tools. 20pcs grinding drill bits are separately packed in small pockets of a bag, easy to place and carry. Specifications: Color: Silver Shank Size: 3mm(1/8 inch) Packing List: 20 * Grinding Drill Bits Package List 20 * Grinding Drill Bits