[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 or 0.24 inch, 8mm or 0.31 inch, 10mm or 0.39 inch, 12mm or 0.47 inch, 14mm or 0.55 inch, 16mm or 0.63 inch, 18mm or 0.71 inch, 20mm or 0.79 inch, 22mm or 0.87 inch, 25mm or 0.98 inch, 26mm or 1.02 inch, 28mm or 1.1 inch, 30mm or 1.18 inch, 40mm or 1.57 inch, 50mm or 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 and silver Material: metal and 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.