Our washers
Depending on your application and headers/primaries, you might or might not need a washer. Copper is a ductile metal that, well known for its malleable properties, and is an excellent conductor of heat. These corrosion-resistant washers will compress for a tight fit and further reduce the chance of unscrewing. They will avoid the nut and the exhaust manifold to rub together and avoid corrosion or damage.