Screwing, Drilling Accessories -Diamond Wood Drill Bits Concrete Countersink Drill Bits Highlights brand generic Diamond Wood Drill Bits Concrete Countersink Drill Bits Description: 100% brand new and high quality Mainly used for drilling porcelain tiles, tiles ceramic, marble, granite, rebar concrete and other hard materials. Need cooling and lubrication, always use lubrication (water), otherwise the diamond core will overheat. Diamond hole saw ceramic, glass and ceramic marble drill. Can be used with a standard electric drill. Specification: Material: Diamond Color: Gold Diameter: Approx. 20mm, 22mm, 25mm, 27mm, 30mm, 32mm, 38mm, 40mm, 44mm, 51mm, 56mm, 63mm, 71mm, 76mm, 83mm, 89mm, 96mm Length: approx. 370mm / 14.57inch Package Include: 2pcs Drill Bit Note: The color may have different as the difference display, pls understand. Please allow 1-3mm error due to hand test.