- Professional 85mm diamond drill bit with centering guide for clean and precise drilling - Compatible with tiles, porcelain, glass, marble, and ceramic, ideal for DIY and professional work - Vacuum brazing technology ensures greater durability and wear resistance - Design with pilot center bit prevents slipping and improves accuracy - Thick and uniform diamond coating for fast and efficient cuts - Side hole allows water cooling and facilitates chip removal - It is recommended to drill vertically and maintain water cooling for optimal performance - Suggested working speed: 500-800 RPM to extend the drill bit's lifespan