Features： 1、DIAMOND MATERIAL: Made of diamond material, the hole opener is strong and sturdy, wear resistant, ensures a long life span. 2、WIDE APPLICATION: The hole opener can be used for glass, ceramic tile, marble, ceramic. But the opener cannot be used for metal. 3、WORK WITH DRILL: The hole opener works with standard drill is able to provide a faster and cleaner cutting work. 4、EASY TO USE: The opener only needs water to lubricate. Keep using lubricating oil or water, otherwise the drill bit will burn. 5、PACKAGE INCLUDES: There are 15 pieces openers in different size that you can use them respectively to meet your different needs. Specification： Item Type: Diamond Drill Bit Material: Diamond Product Weight: Approx. 300 g / 10.6 oz Product Size: Approx. 12.5 x 5.5 x 9cm / 4.9 x 2.2 x 3.5in Application: Used for perforation of glass, marble, ceramic tile, ceramic tile Package List： 15 x Diamond Drill Bit