characteristic: This suit can be used to deal with all kinds of hard materials, such as porcelain, tiles, ceramics, , marble and so on. Our drill bit adopts vacuum brazing diamond technology, which is very suitable for drilling accurate and clean holes in challenging materials. Our diamond bit is filled with wax lubricant, which will melt during drilling and cool the cutting surface. Water can be added for additional cooling and to extend the life of the drill bit. Diamond coating improves drilling speed, and round handle is suitable for most machines. Quick-change hexagonal handle is suitable for most hand drills and bench drills, which is easier and and will not and fall off. describe Name: brazed drill bit set Material: Metal+Sandstone colour: Black Package Contents: 1 x Brazing drill bit set Only 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.