The Edelbrock Replacement Gasket for the Edelbrock Header is made of a compressed fiber laminate with a stock port style. They prevent fluid or gas leaks by providing a barrier between two mating surfaces. The gasket must be able to maintain a seal under pressure and temperature changes. When installing new Edelbrock headers or putting them back on after working on your vehicle, it's very important to use a new set of gaskets. These gaskets provide a tight seal and perfect fit.