The OEMTOOLS Triple Square Bit Socket 10-pc Set, No. 22711, is ideal for working on most European vehicles, including BMW, Mercedes, VW, Audi, and Porsche. Bit sizes include M4, M5, M6, M8, M9, M10, M12, M14, M15, and M16. The hard wearing bits are made of heat-treated alloy steel while the reinforced chrome vanadium steel sockets are designed to give extra turning power. The bits have been treated with zinc oxide to prevent rust and corrosion. This set exceeds ANSI standards and comes in a sturdy blow molded case for convenient and organized storage.