1.Various sizes of dry core drill bits: The diamond drill bit set contains 5 pieces of dry drill bits of different sizes, including 2 3/16 inch (5 mm), 1 1/4 inch (6 mm), 1 5/16 Inch (8 mm), 1 3/8 inch (10 mm), 1 1/2 inch (12 mm). 2.Upgraded dry drill design: Mgtgbao diamond drill bit is integrated with wax lubricant, which can melt and cool the cutting surface during dry drilling; water can be used as additional cooling to extend the life of the drill bit. Surface plating can prevent the drill bit from rusting 3.Widely used: Mgtgbao dry drill set can be used to drill holes in hard materials, especially suitable for ceramic tiles, porcelain, granite ceramic glass mirror marble stone masonry, etc.; Note: Not suitable for wood. 4.Wide compatibility: The black diamond drill is designed with round shank, compatible with most machines, such as manual drills, angle grinders, bench drills, and can also be equipped with side grooves to help remove debris and fast drilling; depth marks can also be used for precision project. 5.Easy to carry The diamond bit is stored in the gray box. After use, it can be stored in the box.