Fel-Pro's exhuast header gasket facing consists of high-density fiber attached to both sides of a perforated steel core. The fiber has great torque retention qualities. These Fel-Pro gaskets can even seal slightly warped surfaces, as well as resist blowout/burnout from high-temp exhaust gases. In addition, a nonstick coating allows motion without gasket damage, and it makes gasket removal easier for future servicing.