【Size】Diameter 1-1/8''(28mm); Total length 65mm; Diamond height 10mm; Triangle Shank; Handle diameter 10mm; Diamond Grit #40/45 【Application】Dry/wet drilling for Porcelain Tile Ceramic Granite Marble Artificial Stone Quartz, etc 【U-grooves Design】4pcs U-grooves helps heat dissipation and debris removal, with higher efficiency and better performance 【High Performance】High-quality Diamond Grain and Vacuum Brazing Technology provides much longer working life, fast and smooth drlling, durable and sturdy 【Recommended Machine】Corded Drill, Cordless Drill, Benchtop Drill. Use electric hand drill: Recommended speed not less than 2000RPM; Faster the RPM, longer the drill bit's working life. When use Angle Grinder, please install angle grinder drill chuck