1、NEAT OPENING AND WEAR RESISTANT: Drill bit bring neat and smooth opening, no broken edges, no need to add water, of sharpness and wear resistant 2、FOR VARIOUS SURFACE: M14 thread brazed mouth angle grinder is made of fine natural diamond powder, suitable for marble, glass, tile 3、LARGE TORSION AND RUST PROOF: M14 screw design, handle can prevent slipping, possess large torsion, high bearing capacity. Using aluminum box for preservation, rust proof and corrosion resistant, possess smooth and high end appearance 4、IMPROVE SERVICE LIFE: Adopt thicken emery coating, the coating is uniform, the wear resistance and the life of hole opener are improved, which means that this products has higher quality and can drill deep holes stably 5、ROBUST AND DURABLE: The cutting blade of the diamond hole saw is made of good quality diamond for more efficient performance than conventional carbide or bimetal hole saws