Universal Hex Shank -- fit a of quick-change chucks, drills or drivers; Add Versatility to Your Tool: 3 Pieces of Dry Diamond Core Drill Bits Kit for drilling holes diameter of 1/4 inch(6mm), 3/8inch (10mm), 5/16inch (8mm). Vacuum Brazed Diamond Technology: Great for drilling clean holes to hard materials especially tiles, porcelain ground, ceramic glass mirror marble stone masonry brick (not for wood). High quality, temperature-resistant diamond grit for efficient, clean bores. Filled with cooling wax and suitable for dry drilling. The use of water or coolant is recommended for a longer service life, Not a disposable product, it can be reused many times! ! Unique Details: Diamond coating enhances the drilling speed; Hex Shank compatible with most machines such as Hand Drill, Angle Grinder, Bench Drill; Side help to remove debris and drill holes smooth and fast; Depth mark useful for precise project. Application: Glass, Tiles and Hard Ceramic Tiles, Porcelain, Marble, Quartz, Limestone, Fiberglass, Terrazzo, Porcelain Stoneware, Masonry, Sandstone. Shank Type: Hex Shank Steps to drill clean and precise holes: Place the drill at a 45 degree angle, so the drill has the chance to start and will prevent the drill slipping Slowly move the drill bit into a more up-right position and Continue to drill and swaying the machine along a circle You don't need to apply too much pressure to let the drill the work. Once the drilling is completed, you will feel the drill break through the back of glass or ceramic tile Be careful when using, because if you use it too fast, it may burn a little glaze and burn out Colour: black Material: emery, hard alloy Package Contents: 1 * Bits diameter of 1/4 inch (6mm) 1 * Bit diameter of 3/8inch (10mm) 1 * Bit diameterof 5/16inch (8mm) Only the above package content, other products are not included. Note: Light 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.