4pc's - dry diamond bit with hexagonal . Dimensions: 1/4 inch (6mm), 5/16 inch (8mm), 3/8 inch (10mm), 1/2 inch (12mm)Application - Diamond bits are designed for use in , , granite, , masonry, concrete, various types of tiles and .Performance - Vacuum brazing diamond technology provides fast, chip-free holes while maintaining a long service life.Tool handle - The quick-change hexagonal tool handle provides better chuck grip and is suitable for different types of drill bits.Self-cooling - diamond bit is combined with wax. Wax melts during drilling, absorbs and dissipates heat, thus achieving dry drilling (water can be added to prolong the service life and harder ).Color: blackMaterial: metalPackage Contents:4 x drill bitsOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.