Spectre offers various size header collector gasket sets from 2-1/2 inches to 3-1/2 inches. We also offer collector reducer sets as well. Spectre header gaskets are made from compressed ceramic fiber (CCF). CCF far exceeds typical non-asbestos type gaskets and are designed to not deteriorate or crack from excessive heat or pressure. Our extra thick 1/8 inch gaskets provide superior sealing with even, uneven or slightly warped header flanges.