30pc Medium 120-150 Grit Diamond Burrs, 1/8 inch shank. Packaged in a brittle plastic box, so the box might be broken or the bits might be bulk. For use with Dremel Type Rotary Tools. Diamond coated accessories will cut into glass, wood, metal, stone, practically anything. Could vary from picture. For longer life, use with a cooling agent such as Eurotool Cut Lube.