This Diamond Drill is used to drill holes. It can be used on Glass， Marble， Granite， Fiberglass， Ceramic and Porcelain Tile. The end of this drill bit is grooved so the diamond coating has better adhesion for longer life， and the side hole allows water to lubricate the inside of the drill bit to insure an ly smooth and perfect hole.                                    Features            The end of this drill bit is grooved， so the diamond coating has better adhesion for longer lifeThe side hole allows water to lubricate inside of the drill bit to insure an ly smooth and perfect holeThis bit can be used on glass， marble， granite， fiberglass， ceramic and porcelain tile                                                            Specifications            Lenght    2"(50mm)     <br>Chuck Size    1/2"(12mm)    <br>Quantity    5Pcs    <br>Weight    0.42 oz /12 g    <br>                                                            Package Includes            5x Diamond Drill