1Adopted of high quality S2 quality steel, which is anti-impact and tough, great wear resistant. 2There are different sizes of screwdriver bit heads, T6, T7, T 8, T10, T15, T20, T25, T27, T30, T40. So is convenient to you, can meet your varied requirements. 3Using the correct screwdriver bar, pay the less effort, and can easily unscrew the screws 4Exquisite workmanship, each edge can be accurately locked screws, no damage to the screw, and the screwdriver head. 5Suitable for professional maintenance personnel, computer maintenance, camera maintenance, eyeglasses maintenance, instrument maintenance, manual electric screwdriver.Description:These screwdriver bits are adopted of S2 quality steel, which is anti-impact and tough, great wear resistant. Exquisite workmanship, each edge can be accurately locked screws, no damage to the screw, and the screwdriver head.Features: Adopted of high quality S2 quality steel, which is anti-impact and tough, great wear resistant. There are different sizes of screwdriver bit heads, T6, T7, T 8, T10, T15, T20, T25, T27, T30, T40. So is convenient to you, can meet your varied requirements. Using the correct screwdriver bar, pay the less effort, and can easily unscrew the screws Exquisite workmanship, each edge can be accurately locked screws, no damage to the screw, and the screwdriver head. Suitable for professional maintenance personnel, computer maintenance, camera maintenance, eyeglasses maintenance, instrument maintenance, manual electric screwdriver. Specifications:Materials: S2 alloy steelHardness: HRC60Size of Bit: T6, T7, T 8, T10, T15, T20, T25, T27, T30, T40Content:1 x 100mm*T6 1 x 100mm*T71 x 100mm*T 81 x 100mm*T101 x 100mm*T151 x 100mm*T201 x 100mm*T251 x 100mm*T271 x 100mm*T301 x 100mm*T40Package Included:1 Set x Screwdriver Bit(include 10pcs)