For use with steel or aluminum wheels with exposed decorative lug nuts that are tapered at the bottom. The extra narrow pattern groove on the lock resists the intrusion of removal tools into the pattern. Every McGard wheel lock is fully machined from restricted chemistry steel made specifically for McGard and through-hardened for its unsurpassed level of security. McGard's plating process includes three layers of nickel and one layer of microporous chrome/black producing a superior finish while protecting against rust. Core integrity and precision machining provide the highest strength in the industry. All McGard lug nuts meet or exceed the highest OEM proof load standards, 135,000 to 160,000 PSI.