Provides longer drilling life, faster and free machining action and more consistent performance.Professional Diamond Coated is for great cutting performance in tile and glass.Tile diameter: 28mmWeight: 78gHardness gives the 28mm Glass the ability to cut through most materials such as glass, ceramic, marble and so on, however, not designed to be used on wood or metal.Metal shaft and tiny diamond particles coated tip of the 28mm Tile for strength and long lasting.Package Content: 2 x Diamond Coated 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.