Package Include-----Total 11pcs/box: 9pcs core drill bits 6/8/10/25/28/32/35/45/65mm with triangle shank; 1pc 20mm drilling milling bit with triangle shank; 1pc 50mm beveling chamfer bit with hex shank Application-----Suitable for dry/wet drilling in Porcelain Ceramic Tile Marble Granite Artificial Stone Quartz, etc. Drilling milling bit for drilling and shape, enlarge and round bevel existing holes. Beveling chamfer bit for shape, enlarge and round bevel existing holes. Triangular shank design for stable clamping, smooth and easy drilling High-quality Diamond and Vacuum Brazed-----High-quality base steel, high-quality diamond provides to improve the efficiency of hole drilling. Vacuum brazed technology provides higher processing efficiency and longer working life. Dry or Wet use. Wet using will prolong the working life and get better drilling effect EVA Mold Positioner-----Built-in sponge pad can effectively fix the drilling position of the hole saw, assist in positioning (drilling a small slot can remove the sponge pad), making the drilling more accurate. Carrying strap on the outside of Oxford bag, easy to carry 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