Model: JKT09 - Quantity: 1 - Color: Silver - Material: Hard alloy - Diameter: 12mm - Triangle ceramic glass drill bit diamond wheel sharpening carbide tips for accurate centering drilling high temperature brazing carbide tips straight drill shank. - Suitable for hard and brittle materials such as ceramics glass granite tile and brick walls. - Meets the national standard specifications make sure that the openings neat smooth and without broken edges which will not produce tremor phenomenon. - Long lifetime and high quality. - It can be mounted on an ordinary hand drill. Need to add coolant (water turpentine or gasoline) please make your drilling gently.