[Sturdy, Sharp, Long Service Life]The 15-piece hole saw is made of diamond-in-one steel, sturdy and durable. The surface adopts high anti-corrosion electroplating process and the top is thickened with diamond coating to provide excellent cutting strength and achieve high-precision and smooth cutting. Reducing the drilling speed and pressure and increasing the use of water lubrication will greatly extend the service life. [Strong suction, precise positioning] The upgraded double suction cup design provides more powerful suction than a single suction cup. Warm tips: 1. Keep ceramic tiles, glass, marble and other surfaces clean and dust-free. 2. Try to expel the air in the suction cup before pulling down the handle. [Easy to use, just 4 steps ] Step 1: Clean the surface and mark the drilling locations. : Place the hole saw into the positioner and adjust the position of the hole. Step 3: Press the double suction cup positioning system of the positioner and fix the hole saw by adjusting the positioning shaft wheel. Step 4: Complete the drilling work under water lubrication. [Package Content]15 pieces professional integrated steel diamond hole saw: 6mm/0.24 inch, 8mm/0.31 inch, 10mm/0.39 inch, 12mm/0.47 inch, 14mm/0.55 inch, 16mm/0.63 inch, 18mm/0.71 inch, 20mm/ 0.79 inch, 22mm / 0.87 inch, 25mm / 0.98 inch, 26mm / 1.02 inch, 28mm / 1.1 inch, 30mm / 1.18 inch, 40mm / 1.57 inch, 50mm / 1.97 inch. 1 piece of double suction cup tile hole locator, 1 piece of screwdriver for cleaning debris left in the hole saw after drilling Color: green + silver Material: metal + plastic Package Contents: 1 x drill bit set Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.