Feature:This diamond coated core drill bit removes a complete circle from tile, ceramic or other materials and only needs water for lubrication.Excellent for making clean and accurate hole on tile .High quality and long life span.Start your hole diagonally, make a round trace and then hold drill straight.Add water for coolant and drill slowly.Specification:Material:Metal,DiamondColor:SilverShank Diameter: 2.3MMHead Diameter: 1mmSand length: 6-8MMFull length: 42mmDimension:2.3 x 42mm/0.09 x 1.65 inch(Dia x L)Weight:24gNote:There would be some deviation. Before buying, please check the product size.Warm reminder: Drill bit generally need to be drill slowly on the stone when start to drill, wait for the stone to open hole and then drill hard. Like hard stones, or ice types, miscellaneous stone, agate, etc., the punch needle may not be durable. If it is used on hard stone, it is recommended to add emulsified oil to lubricate the Drill bit.Package Include:20 x Diamond Coated HOLE Drill Drills