IVY Classic 37806 Diamond Plus 1/2-Inch Wet and Dry Cutting Diamond Grit Hole Saw, 1/Card Designed to drill holes in porcelain, hard tile, quarry tile, granite tile and glass, rotary drilling only, Diamond Plus (Registered Trademark) Vacuum-brazed diamond grit ensures long life For wet and dry cutting, use with low RPM and minimal pressure. For cool cutting lubricate with water for extended life Slot in hole saw provides easy plug removal Diameter: 1/2-inch, Overall length: 2-3/16-inch, 3/8-inch hex shank