The Edelbrock Air Horn Gasket is designed for Performer RPM cylinder heads and manifolds for optimum flow and performance, and sealing is improved with a silicone bead. It allows for taking off the top of the Edelbrock carburetor when changing jets or metering rods. They include five air horn gaskets to make multiple changes. It is made of high-density non-asbestos fiber/metal reinforced composite material that is bonded to a metal core.