Feature: 1. The head is brazed with emery, filled with secret cooling wax for cooling and lubrication 2. Recommended used for angle grinder (a replacement adapter is required). The rotation speed of the angle grinder is tens of thousands, and novices can easily use it. Under reasonable operation, the average punching time of each hole is about 15-20 seconds, punching is efficient, and the service life is stable 3. The upgraded version of the drill bit is directly dry-driving without adding water, replacing the triangular drill and tile hole opener on the market 4. Suitable for all kinds of all-ceramic tiles (vitrified tiles, polished tiles, glazed tiles, antique tiles, floor tiles, microcrystalline tiles), quartz stone, granite, ceramic tiles and other hard and brittle materials. 5. Suitable for electric hand drills, bench drills and other equipment, durable and possess long service life Specification: Item Type: Brazed Dry Drill Bit Material: Diamond Colour: Black Features: No need to add water Specification: Approx. 10mm / 0.4in Applicable Equipment: Electric hand drill, bench drill and other equipmentHandle Height: Approx. 40mm / 1.6in Cutter Head: Approx. 10mm / 0.4in Diameter: Approx. 10mm / 0.4in Total Length: Approx. 80mm / 3.1in. Package List: 3 x Brazed Dry Drill Bit