The 15pcs hole saws, different sizes, are used to drill holes for glass, ceramic, marble, tile and granite. Features: Made of high strength carbon steel with smooth nickel plating surface, glass drill bit set lower resisting force to the minimum, makes it easy to drill precise holes In Seconds. Each diamond hole saw was processed by a smooth and exact finish that lower the incision resistance and drill pressure, increase the sharpness and the use of water lubrication. It is perfect for glass, ceramic, marble, tile, granite. Simple to operate and convenient to use. The diamond coated core drill bit removes a complete circle from glass, tiles, marble, granite, ceramic or other materials. Works better with a electric drill. Specifications: Material: Diamond Color: Silver Quantity: 15Pcs Diameter: 6/8/10/12/14/16/18/20/22/25/26/28/30/40/50mm Package Weight: 391g / 13.79ounces Package Size: 120 * 100 * 40mm / 4.72 * 3.94 * 1.57in Packing List: 15 * Hole Saws