1/4 Inch Diamond Drill Bit Kit: you will get 12 diamond drill bits measuring 1/4 inch (6 mm) in diameter, practical supplies for home or work, sufficient for daily replacement needs Wax Lubricant for Cooling: these diamond drill bits for ceramic have applied wax lubricant inside diamond drill bits, cooling the cutting ; Additionally, the drill bit is made of cemented carbide that is sturdy, not easy to break Light weight makes the tile core bits easy to carry Drill Hard Materials: since the drill bit itself is hard, diamond bits for drill are suitable to drill holes on hard materials, such as ceramic tiles, porcelain, , ceramics, glass, marble stone bricks and so on; Note: these tile core bits are not suitable for wood Good Compatibility: the diamond core drill bit is compatible with many machines, such as hand drills, angle grinders and bench drills; There are depth markings on the diamond drill bits, useful for accurate measurements Colour:blue Material:Brazed Diamond Package