It features cold formed chrome-vanadium (CR-V) steel socket base and heat treated S2 tool steel bits for outstanding durability and strength. This triple square bit set let you handle more torque to get your jobs done faster. It is ideal for using with torque ratchets and breaker bars. This set is compatible with most European vehicles such as Volvo, Audi, Porsche and so on. Chamfered bits ensure a perfect fit and make it extremely accurate with very close tolerance Fully polished chrome finish resists rust and corrosion and easily wipes clean of oil and dirt.