Tri-bit design: cutting edge CNC grinding teeth, tricuspid centering is better, will not produce offset, quasi-drilling and fast. High carbon steel material: quenching, high hardness, good abrasion resistance, durable. Round handle design: suitable for the market bench drill, the use of more convenient. Removable Adjustable: use a wrench to remove or adjust woodworking and five-bevel chamfering. Reduce labor intensity of construction workers, speed up the construction speed, reduce construction costs for construction, installation, renovation, decoration industries.