Features: Size: 50 mm. Suitable for stone, tiles, ceramics, glass, etc. Centrally positioned drill bit helps cut precise holes. Long service life: Reduced drilling speed, low drilling pressure, and increased use of water lubrication extend the service life of the drill bit. p> Through hole: Diamond drill bits with a through hole facilitate the entry of cooling water and the removal of drilling chips. Simplifies the drilling process. Clean, smooth cut: The diamond hole saw produces high-precision, smooth cuts without broken edges. The white zinc plating of the bits maximizes tool life with excellent corrosion resistance. Tips: Please use at low drilling speed and low drilling pressure. Always work with coolant (water) when drilling. Not suitable for drilling tempered glass, plastic, and wood. Not suitable for use on concrete or for depths greater than approximately 1/2 inch. Description: 1. Smooth and precise surface to reduce cutting resistance and drilling pressure, and increase