[Professional Diamond Drill Bits] -- ConBlom Dry Type Ceramic Tile Drill Bits are welded and can be used without adding water. 7 different specification marble hole drill bits, 5/6/8/10 /12/14/16 mm, which can meet to your different needs [Fast and Smooth Drilling] -- The diamond drill bit adopts scientific chip removal design, and overall forging, make the drill body more stable without chattering. Less material loss. Less heat generation. drill at FULL SPEED [High Quality Materials] -- The diamond drill bit is made of high quality emery electroplating, high temperature quenching, high hardness, sharp and durable. Internal sealing wax, solid condensation processing, more durable use [Wide Application] -- The back of the diamond drill bits has a circular design which is widely used in hand drills and angle grinders. Ideal for solid ceramic tiles, marble, granite, ceramics, glass ordinary, etc. [Package] -- What you will get: 7 different specifications of marble hole drill bits (5/6/8/10/12/14/16mm).