Features: Advantages: upgraded four-edged, fast drilling speed. Non-slip hex handle, not easy to cause trouble in operation. Made of Hard Alloy Material, Hard and Wear-resistant. High Hardness ,Wearing -resisting Long Life When working at high speed ,increase the discharge of waste to prevent blocking the hole Using ceramic tiles, brick walls, concrete, glass, ceramics, wood, aluminum alloy, plastic steel and other materials Specifications: Material:Hard Metal Color:Brown Type:Center Drill Bit Size1:Approx. 10mm/0.39inch Size2:Approx. 12mm/1.2inch Size3:Approx. 3mm/0.11inch Size4:Approx. 4mm/0.15inch Size5:Approx. 5mm/0.19inch Size6:Approx. 6mm/0.23inch Size7:Approx. 8mm/0.31inch Note: 1.when drilling continuously, it is necessary to add water to cool it to avoid the bit burnt. For example: ceramic tiles, vitrified tiles, glass, marble, etc. 2.Please allow 1-2mm errors due to manual measurement, make sure that you do not mind before you order. 3.Due to the difference between different monitors, the picture may not reflect the actual color of the item.. Package includes: 1x Hexagonal Drill