Professional multi size: T8, T10, T15, T20, T25, T27, T30, T40 Type of shank: 6.35mm / 1/4 inch hex. Overall length: 150mm / 5.9 inch Made of high-strength S2 Alloy Steel, a commonly used material in hardware with high hardness All torx bits have a centre bore. Bits with magnetic, can be firmly fixed on screwdrivers Widely Using Application: Can be used for manual electric screwdriver, screwdriver, drill, air and other tools