Drilax&trade; 2-1/2 Diamond Drill Bit Hole Saw for Ceramic, Porcelain Tiles, Glass, Fish Tanks, Marble, Granite, Quartz Diamond Coated Circular Saw - Kitchen, Bathroom, Shower, Faucet Wet Drilling Tool 2.5 Inches in Drilax010065 Durable Diamond Drilling Holesaw Tool 2 1/2" - 2.5 inches Over 80% cost savings compared to big box stores. Use with standard electric or battery drillers. There is no need for a center pilot drill. These tools do not have center pilot drills. Do NOT run dry. Diamond Coated Tools will work best if you use water to keep the tools cool. Shank sizes vary, maximum shank is 3/8" - suitable for all common electric drillers.