Features:* Can be used to drill holes in many kinds of materials, such as glass, tile, marble, granite, ceramic, etc.* Made of high-quality material, durable and sturdy * Can be used with a standard electric drill (not included)* Easy to use: start the hole diagonally, make a circular trace, and then hold the drill straightSpecifications:Product Name: drill bitMaterial: DiamondsColor: SilverLength: 50mm/1.96 inchDrilling Size: 3/5/6/8/10/12/16/18/20/30/40/50/60/70mmQuantity: 14 PiecesWarm Tips: During the process of use, please add water to cool down and adjust the suitable speed, which can avoid the high temperature of superheating burning the drill bit cutter. Package Contents:14pcs Set Drill Cutter