Bulk Packaged 20pc 150 Grit Titanium Nitride Coated Diamond Burr Set, 1/8 inch shank. Diamond Coated Burrs that have a Titanium Nitride coating for cooler operation and longer life. 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. May vary slightly from picture.