Features: 1. Material: This diamond grinding bits is made of sturdy and wear-resistant diamond particles with uniform grit and high hardness. Great for polishing stone, glass, ceramics, engraving 2. Different Shapes of Polishing Kit: Our polishing kit has 6 different grinding bits to meet the needs of different scenarios. Commonly used in fine engraving, jewelry processing, cutting glass, stone and ceramics, etc. 3. 1/8 Inch shank , compatible with most rotary tools and drills. Grinding head size: 6mm. 4. Includes 20 pieces with sturdy plastic case. 5. Wide range of applications: ideal for precision detail work, polishing, grinding, cutting, engraving, carving, trimming and finishing. 6. High quality: If you have any problem, please feel free to contact us. Warm Tips: 1. When utilizing this product, please ensure an adequate amount of water is added. Additionally, it is imperative to wear a dust mask and protective eyewear to prevent any debris from entering the eyes and respiratory system. 2. The installation of the mandrel must be securely tightened, and the operating speed should not exceed 20,000 RPM. Exceeding this speed limit may result in rod fracture. 3. diamond grinding head is particularly well-suited for processing high-hardness alloys and non-metallic superhard materials. Different configurations of the diamond grinding head serve distinct purposes, including engraving, grinding, polishing, and milling.