TPI (4 Locks) Aluminum Head Locking Bolt, M14x1.50, 28mm Shank Length, CAL2527BC-4728Z-TPI,Annodized Black, 19mm Hex, 4 Locks + 1 Key per Clam, Cone Seat, Porsche, Audi The Aluminum nut top is made of material AL7075 heat-treated, soft-anodized with a polished top and sand-blasted sides for a high-end effect. TPi special patented Press-In-Pin design fixes the nut firmly to the stud, to assure high endurance and safety. TPi Duralumin Head gives greater color options for European wheels and vehicles with bolt use. Annodized Color for a long lasting look 4 Locks + 1 Key per Clam