Hard and Sharp: Made of high-speed steel, heat-treated, high-quality workmanship, sharp and durableThree-point design: CNC grinding for grooving and milling, better cutting effect three-point bit centering Adjustable depth: use a hex wrench to replace or remove the five-edged chamferQuick chip removal: wide flutes and five-edged chamfer remove balsa chipsShank: Round shank design is smooth, frictionless with machinery and fits most hand or bench drills< /ul > - Try to keep the bit vertical when drilling, and do not make the bit surface or bevel uneven. Package Contents: 7 x Countersunk Bits ( 1 x Hex WrenchNote: The data is all measured manually, please allow error of 1-3cm, due to the difference in light and display, there will be a certain color difference, the actual object received shall prevail.