This ultra-seal exhaust gasket is made of high temperature steel core/graphite faced exhaust material which seals the connection between the manifold and cylinder head. It prevents exhaust leakage out of the connection and also ensures that all exhaust gas will flow through the catalytic converter for treatment. Flange and ring gaskets seal other connection points in the exhaust system. It can be trimmed for modified ports and is packaged 2 per set. V6 and V8 engines require two manifold gaskets.