Welcome To Our store ! Made of high quality diamond material with fine workmanship, it is very durable, wear-resistant and easy to use. During processing, it has the advantages of no chipping, fast speed, sharpness and wear resistance. It is suitable for drilling stone, ceramics, vitrified tiles, glass, etc. Item Name: Hole Opener Material: Diamond Drill Bit Models: 50mm, 55mm, 60mm, 65mm, 70mm, 80mm, 85mm, 90mm Features: Fast Drilling Speed, Long-Lasting, Durable, Wear-Resistant, Easy to Use Size: 50mm/1.97", 55mm/2.17", 60mm/2.36", 65mm/2.56", 70mm/2.76", 80mm/3.15", 85mm/3.35", 90mm/3.54" (Approx.) Notes: You will find more amazing products if you visit our store. First, it is positioned at a 45 inch bevel, and drills vertically, the speed should not be too fast, then the speed should be slowly operated at about 800-1000 rpm, and water must be added to cool the operation. Due to differences in lighting and screen settings, the color of the project may be slightly different from the picture. Due to different manual measurements,allow for slight size differences. Package Includes: 1 x Hole Opener