Bulk Packaged 4.9 x 10.5 mm, 3/16 x 13/32 inch 150 Grit Flame Diamond Coated Burr, 3mm shank can be used with a keyless chuck. For use with Dremel Rotary Tools. Diamond coated accessories will cut into glass, wood, metal, stone, practically anything. For longer life, use with a cooling agent such as Eurotool Cut Lube.