Kit includes standard/stainless steel/double lok ENP bit pack, 10-15 and 20-25 torx. Replacement bits are made from professional quality S2 steel for the right combination of strength and durability. The electro less Nickel plated "ENP" bits provide outstanding protection from rust and corrosion. The Replacement Bit Packs T2D10-15S, T2D20-25S are for the 15-in-1 Original, 15-in-1 Stainless, 14-in-1 MegaLok and the 13-in-1 Ratcheting drivers. They are nickel plated bits and measure 1/4-Inch by 2-Inch. They store easily in the patented pullout bit cartridge in the screwdrivers. Both ends lock into all drills with a 1/4-Inch quick change chuck. The T2D10-15S is a Star(Torx) DoubleLok bit 10-15 Nickel Plated and the T2D20-25S is a Star(Torx) DoubleLok bit 20-25 Nickel Plated.