【Size】Totally 10pcs/set: Diameter 8pcs 6/8/10/12mm drill bits+2pcs 6mm carbide drill; total length 65mm; diamond height 8mm; diamond grit #50/60; round shank 【Application】Suitable for dry or wet drilling in Porcelain Ceramic Tile Marble Granite Artificial Stone Quartz, etc. Wet using will prolong the working life. Round shank design for stable clamping, smooth and easy drilling 【Cooling Wax & Vacuum Brazed Technology】The inside of drill bits are filled with cooling wax, help heat dissipation and chip evacuation. Vacuum brazed technology and high-quality diamond grains 【Cross Helix Carbide Drill】Cross Helix Carbide Drill sloves the problem of diamond bit drifting and walking. Provide more precise positioning and easier drilling 【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