Drilax&trade; 3 Pcs Diamond Drill Bit Set 1/2" 3/4", 1" - Wet Cutting Drilling Tiles, Glass, Fish Tanks, Marble, Granite, Ceramic, Porcelain, Bottles, Quartz Sinks, Lot 3 Diamond Coated Core Holesaw Kitchen, Bathroom, Shower, Faucet Drilax031325 Perfect Diamond Drilling Tool Set for Small DIY - 3 Common Sizes: 1/2" 3/4" and 1" 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. These Diamond Coated Tools will work best if you use water to keep the tools cool. For Ceramic and Porcelain Tiles, Glass, Fish Tanks, Aquariums, Marble, Granite, etc.