TOO DIAMOND SAW 10 SIZES 6mm/0.23", 8mm/0.31", 10mm/0.39", 12mm/0.47", 20mm/0.78", 25mm/0.98", 30mm/1.18", 35mm/1.38", 40mm/1.57", 50mm/1.97". They are made of high-strength carbon steel, which makes these diamond drill bits durable. TOO ADJUSTABLE SAW DRILL GUIDEAdjustable Hole Saw Drill Guide Attachment with Suction Cup - the length of the hole saw is adjustable. Maximum board opening is 3-1/4", which is large enough to fit all size hole saws. Movable ball bearings, two modes (3 or 4 bearing attachment) are your choice , just flip the board. HIGH QUALITYThese diamond drill bits are made of industrial grade carbon steel and are nickel plated to resist corrosion.Coated with high quality diamond, the Diamond hole saw creates a smooth, high-precision cut with no broken edges.Reduced drill speeds, low drill pressure and increased use of water lubrication will significantly extend drill bit life. < p>WIDE USEThis diamond core bit can be used to remove rings on glass, marble, tile, ceramic, PVC or other materials. When the diamond drill bit is working, please keep adding water to reduce the drilling speed, reduce the drilling pressure, and increase the lubricity of water, which will greatly extend the service life of the drill bit. ERGONOMIC DESIGN Large clearance holes along the drill bit make it easy for cooling water to enter and chips and other particles to escape from the drill hole, ensuring smooth punching and making the process easier drilling. Small Holes - When debris gets stuck in the hole saw. We can use our screwdriver to remove it.