Premium Material: The bit set is made of premium S2 chrome vanadium alloy steel. The coating is black phosphate to resist corrosion and increase the life of the bit, and is rust-proof and corrosion-resistant. 【Package List】 The tool kit includes 13 pieces Torx bits: 1 x T7 / 1 x T8 / 1 x T9 / 1 x T10 / 1 x T15 / 2 x T20 / 2 x T25 / 1 x T27 / 1 x T30 / 1 x T35 / 1 x T40 in 50mm length, with base storage plate. 【Durable】 Heat-treated forged drill bits made of S2 alloy steel to reduce wear. The treated chrome vanadium steel base increases torque and the sturdy screwdriver bit is ideal for particularly heavy-duty work. Easy to install: The impact driver bits are equipped with a 1/4" diameter hex drive handle. Easy to install and disassemble and will not fall off easily during use. Works with quick release holders and all cordless screwdrivers. Wide application: The torx bit set is widely used in hex tools such as pneumatic screwdrivers, electric screwdrivers, manual screwdrivers, etc. An