[High Quality] This diamond drill bit is made of high-quality steel with a diamond powder coating for corrosion resistance. The thickened diamond coating on top provides excellent cutting resistance for smooth, high-precision cuts without the need for edging, ensuring optimal drilling results. [11 Sizes Diamond Hole Saw Bits] This diamond hole saw kit includes 11 different bits to meet your various needs. It includes the following diameters: 5mm, 6mm, 8mm, 10mm, 12mm, 20mm, 25mm, 30mm, 35mm, 40mm, and 50mm. Made of high-strength 45 steel, the integrated steel frame makes these diamond bits more durable. [Adjustable Hole Saw Drill Guide] The guide features a suction cup base for secure mounting. The maximum opening length of the plates is 4 to 83 mm, large enough to accommodate all hole saw sizes. The removable ball bearings are available in two models (fixed bearings, 3 or 4) – just flip the board. [Ergonomic Design] The large safety hole on the drill bit allows cooling water to enter, preventing chips and other particles from entering the drill hole, ensuring smooth drilling and facilitating the drilling process. A small hole is included for when debris gets stuck in the hole saw. This can be removed with a screwdriver, providing a perfect drilling experience. [Wide Application] This diamond hole saw can be used to remove rings from glass, marble, tile, ceramics, PVC, or other materials. When the diamond drill is running, continue to add water and reduce the speed. Hole saw guide. Specification: 11 sizes diamond drill bit Material: High-quality steel, diamond dust coating Size: 5mm, 6mm, 8mm, 10mm, 12mm, 20mm, 25mm, 30mm, 35mm, 40mm, 50mm Material: Rubber base + plastic shell + steel Minimum drill size: 1/8 \" Maximum hole saw size: 3-1/4 \" Weight: 600g Color: Orange Quantity delivered: 11-piece set