Professional Diamond Hole Saws: Diamond coated hole saw drill bit with vacuum brazing technology, ideal for drilling tiles, porcelain, glass, marble, ceramic, etc. Accurate Hole Drilling: With the pilot center drill bit design, avoid slipping problems and make drilling holes on tiles easy and accurate. Durable: Thanks to vacuum brazing technology, the diamond adheres better and improves heat and wear resistance, resulting in superior performance and longer service life. Efficient: The thick and uniform diamond coating allows for fast and effortless cutting. The large clearance hole on the side allows water to continue cooling and easily remove chips.