New box set of 30 pieces diamond coated burrs / pointed heads in box set They will fit your hand drill, drill press & your Dremel, Foredom or other rotary tool with a 1/8″ collet. There are sphere, cylinder, bullet, and needle sharp burrs. Overall length is 40mm to 50mm (1 5/8 inch to 2 inch) Shank diameter : 3.17mm (1/8 inch) premium type diamond coated in GRIT 300 (Fine) these are very fine cutting finishing burrs. They will not remove a lot of material, see our other listings for 40 and 120 grit. suitable for glass, marble, rock or jewelry. please use coolant/lubricant while working with hard materials to increase the life of your burrs. These are our general purpose sets, please see my other listings for specialised sets and other grits.