This is the Subaru OEM Exhaust Manifold Gasket. This gasket will experience more heat than most gaskets in the engine, and after time and mileage, they can become brittle causing an exhaust leak. Anytime you remove the manifold for maintenance or upgrades, it is always a good idea to replace this gasket for preventative maintenance against exhaust leaks.
Subaru Exhaust Manifold Gaskets (Pair): These gaskets connect the exhaust manifold to the cylinder heads.