Diamond Drill Bit Set Various Sizes - Set include 10 holes saw drill bits+1 hole saw guide clamp+1 screwdriver driver + 4 triangle bit. 10 Sizes Diamond hole saw : 6mm, 8mm, 10mm, 12mm, 20mm, 25mm, 30mm, 35mm, 40mm, 50mm,made of high-strength carbon steel, the integrated steel structure makes these diamond drill bits more sturdy. Diameter of triangle bit: 6mm, 8mm, 10mm, 12mm. Rustless & Sturdy: This diamond drill bits are made of high strength Carbon Steel with smooth nickel plating surface. Each diamond hole saw was coated with Diamond to enhance the drilling speed and creates a sharp, high precision and smooth cut with no broken edges In Seconds. Reduced drill speeds, low drill pressure and increased use of water lubrication will extend drill bit life considerably. Adjustable Fixture - Adjustable hole saw drilling guide fixture with suction cup-the maximum opening length of the board is 3-1 / 4 ", which is large enough to fit in all size hole saws. Movable ball bearings, two modes (fixing 3 or 4 bearings) are your choice, just flip the board. The large clearance holes along the drill bit help the entry of cooling water and the escape of chips and other particles from the borehole, ensuring smooth punching and making the drilling process easier. Small holes-When debris gets stuck in the hole saw. We can use our screwdriver to pull it out.