Porsche Titanium Alloy Exhaust Stud Kit for 911 models. Years 1965-1977. These high performance studs + nut kit for the exhaust manifold to the cylinder head for Porsche models use titanium and Inconel alloy studs, aerospace lock nuts, and a well-thought and balanced combination of metals and plating/coatings, our fasteners will perform better than the traditional fastener. One set needed per car. Comes with 12 pieces of each (lock nut, washer and nut)