IAG Performance Exhaust Manifold Gasket Kit w/Copper NutsThe IAG exhaust manifold gasket and hardware kit for the FA20 BRZ includes (x2) exhaust manifold gaskets and a 6 pack of copper exhaust nuts. The copper exhaust nuts are designed to replace the OEM exhaust nuts at the Subaru manifold to cylinder head location. The copper nuts are ovalized and feature a broad flange for improved clamping force.