Osko&reg; 2-3/4"(70mm)diamond Drill Bit Hole Saw for Kitchen, Bathroom, Shower, Faucet Wet Drilling Tool Ceramic, Porcelain Tiles, Glass, Fish Tanks, Marble, Granite, Quartz Diamond Coated Circular Saw 2.75 Inches in 2 3/4 " 45# Steel Base and Type 3 Diamond,For porcelain, glass, marble, ceramic, rock and granite 2-3/4" 70mm Diamond Coated Hole Saw Shank Size 3/8-suitable for all common electric drillers. Over 80% cost savings compared to big box stores. Use with standard electric or battery drillers With Special design of diamond brazing, the edge of saw blade will be free cutting.There is no need There is no need for a center pilot drill. These tools do not have center pilot drills.