Function: Diamond Burr Grinding: 6 shapes, evenly coated with diamond particles, various grinding heads for grinding, engraving, cutting, polishing, engraving and etching, for hard materials such as stone, glass, metal, hardwood, ceramic tile, marble, granite. Diamond Cutting Disc: Evenly coated with diamond particles, suitable for cutting gems, glass, ceramics, tiles, rocks, aluminum and copper. Bit grinding and polishing kits: suitable for cutting, engraving, grinding, polishing, deburring and more. It is suitable for most common rotary tools and can be used with electric grinders or other rotary tools. Specification:Type: Rotary Grinding Tip Material: Metal, Carborundum, etc. Color: As the picture showsQuantity: 42pcsDiamond Burr Grinding: 6mm/0.24in Head, 3mm/0.12in Handle, 45mm/1.77in LengthDiamond Cutting Disc: 22mm/0.87inPackage Included:20 x Diamond Burr Grinding20 x Diamond Cutting Wheel2 x Mandrel