1 They come with universal 1/4 inch Hex Shank, which fit a variety of quick-change chucks, drills or drivers 2 The drill bits set includes 3 sizes of Dry Diamond Core Drill Bits for drilling holes with Diameter of 6mm, 8mm and 10mm, to meet different needs of hole 3 Built with vacuum brazed technology, so the diamond bits can be used at a higher temperature when cutting harder materials It can cut faster and last longer 4 Great for drilling clean holes to granite, ceramic, glass stone brick and marble tile stone Jars and similar materials (not for wood)5 Dry diamond drill bit integrates wax lubricant inside of the bit During drilling, this integrated lubricant will melt to cool the cutting surface, perfect for project which lubricant is not applicable If additional cooling is required, water can be used to prolong the life of the bit and to remove the debris during the drilling process Steps to drill clean and precise holes:1 Start Drilling the hole in an angle about 45 degrees to the surface, so the drill has the chance to start and will prevent the drill slipping 2 Slowly move the drill bit into a more up-right position and wobble the drill bit in the circular motion 3 Do not need to apply much pressure, let the drill bit do the work, you will feel the drill bit break through the back of the glass or tile once the hole is completed 4 Take care when using them as a bit can glaze and burn out if use too fast Colour:blackMaterial:diamondPackage Contents:1 x 6mm Bit1 x 8mm Bit1 x 10mm BitOnly 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