Features 1、Polishing head is made of corundum which is wear resistance, have good polishing effect. 2、It is an efficient polishing tool in small area of rust deburring and surface polishing. 3、Grinding drill with different kinds of sizes, meet your different needs. 4、Used for all kinds of mold, glass, gemstone, jade, stone and hard objects, mold grinding. 5、Suitable for pneumatic, electric rotary grinding machine. Specification Features: Polishing head is made of corundum which is wear resistance, have good polishing effect. It is an efficient polishing tool in small area of rust deburring and surface polishing. Grinding drill with different kinds of sizes, meet your different needs. Used for all kinds of mold, glass, gemstone, jade, stone and hard objects grinding. Suitable for pneumatic, electric rotary grinding machine. Specification: Material: Corundum (electroplating) Shank Diameter: 3mm/0.1in Package List: 20 * Grinding Drill Bit Package List