1/4 Inch Hex Shank Screwdriver Bits SetThis set contents 1 x TS8, 1 x TS10, 1 xTS15, 1 xTS20, 1 xTS25, 1 xTS27, 1 xTS30, 1 xTS40The screwdriver bit is suitable for electric Spanner screwdriver.It is useful to operate electronic device, perfect for electrician, mechanic and repair work.Those Screwdriver Bits are made of S2 alloy steel which is anti-impact and tough, great wear resistantStrong magnetic, good workmanship, high precision. each edge can be accurately locked screws, no damage to the screw and the screwdriver headWith 1/4 inch hex shaft, they are widely used on electric screwdrivers, hand screwdrivers, cordless drills, etcThe screwdriver head is Pentagonal head, which is easy to use.Fit for electric screwdrivers, hand screwdrivers, electric drills, air drills and so forth