Feature: 1. NEAT AND WEAR RESISTANT: Core drill bit bring neat and smooth opening, no broken edges, no need to add water, of sharpness and wear resistant 2. LONG SERVICE LIFE: Thicken emery coating, the coating is uniform, the wear resistance and the life of hole opener are improved, which means that this products are of higher quality and can drill deep holes stably 3. EASY DRILLING: Combining the sharpness of a glass hole saw with the durability of a sintered hole saw, hard tiles and marble can be easily drilled 4. LARGE TORSION AND CORROSION RESISTANT: 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 5. FOR MANY SURFACES: M14 brazed mouth angle grinder is made of fine natural diamond powder, suitable for marble, glass, tile Specification: Item Type: Diamond Hole Saw Kit Material: Diamond Color: Golden Hole Diameter: Approx. 25mm / 0.98in 35mm / 1.38in 50mm / 1.97in 68mm / 2.68in Head Height: Approx. 15mm / 0.59in Working Length: Approx. 40mm / 1.57in Overall Length: Approx. 60mm / 2.36in Female Thread: M14 Scope of Application: Marble, glass, ceramic tile, granite and other stone openings. Package List: 4 x Diamond Drill Bit1 x Aluminum Box1 x User Manual Note: 1. Do not use these drills with hammer.2. Only mount these bits on corded drills, not cordless drills (not enough power).3. Only for tile drilling, not recommended for materials behind tiles.4. For horizontal drilling, just apply light pressure.5. For vertical drilling, the weight of the machine will provide enough pressure.6. Finger drills are used to enlarge, reshape or round the bevel of existing holes.7. Wear all applicable safety gear when using these diamond bits.