Bulk Packaged 1.7 x 11.3 mm, 1/16 x 7/16 inch 400 Grit Cone Diamond Coated Burr, 1/8 inch shank. 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.