Bulk Packaged 6pc 1/8 x 3/8 inch Bullet Diamond Coated Burr, 1/8 inch shank. NOTE: There is some variation in the sizes of these. For use with Dremel Type 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.