What you will get: there are 20 pieces of diamond drill bits in the package, which are sufficient to meet your daily use and replacement needs; You can also share them with your family and friends who love handicraft or who have a job of handicraft Quality material: diamond hole saw drill bits are made of high strength carbon steel, which makes these diamond drill bits and precise, not easy to de suitable form or wear, providing them with a more pointed and a longer service time Great design: diamond coated drill bits are finely made and have a smooth ; Side chip removal holes are designed suitable for easy removal after drilling to improve the speed of drilling and the work more efficiently Wide application: you can safely use the hollow core drill bit, which has a wide range of applications and is suitable suitable for drilling holes of different materials, like glass, tile bottles, blocks jars, fiberglass porcelain tile ceramic, marble, light stone, etc. Size design: this hole saw drill bit is 1/2 inch/ 12 mm in diameter, 20 mm in shank length, with maximum depth of 30 mm borehole, total length of 50 mm; The compact size is suitable for easy use, carrying and store without taking too much space; Please use the drill with enough water suitable for lubrication and cooling size:50 x 6 x 12mm Material:Diamond colour:Silver Package Contents: 20 x Diamond hole saw drill bits Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.