Feature: 1. Processed with fine quality synthetic diamond coating that provides for a more consistent diamond scratch pattern. 2. With air holes designed to aid in and maintain a cool stable cutting pattern and reduced wear. 3. Used on high-speed electric grinder and pneumatic tools. 4. Provides very fast grinding action on masonry, stone and concrete. 5. Generally applicable to the grinding of marble, granite, ceramic, artificial stone and glass, etc. 6. Suitable for people who do granite and marble worktops, headstones, tilers, builders. Specification: Features: Processed with fine quality synthetic diamond coating that provides for a more consistent diamond scratch pattern. With air holes designed to aid in and maintain a cool stable cutting pattern and reduced wear. Used on high-speed electric grinder and pneumatic tools. Provides very fast grinding action on masonry, stone and concrete. Generally applicable to the grinding of marble, granite, ceramic, artificial stone and glass, etc. Suitable for people who do granite and marble worktops, headstones, tilers, builders. Specifications: Material: Diamond Grinding Wheel Production Process: Sintering Color: Blue, Green, Red (Optional) Diameter: 100mm /4in Inner Hole Diameter: 20mm / 0.79in (without metal-ring) Inner Hole Diameter: 16mm / 0.63in (with metal-ring) Thickness: 5mm / 0.2in Package Size: 120 * 120 * 30mm / 4.72 * 4.72 * 1.18in Package Weight: 185g / 6.52ounces Note: 1.Due to the different display screen and light effect, the actual color of the item might be slightly different from the color showed on the pictures. 2.Please allow a little measuring deviation due to manual measurement. Package List: 1 * Grinding Wheel Disc Package List: 1 * Grinding Wheel Disc