Steeda air & oil separators are crafted from aerospace grade billet aluminum for light weight and great looks. They Connect to the PCV hose to prevent oil and crankcase vapors from getting into the intake manifold and decreasing your fuel octane. They are fully sealed to ensure no vacuum leaks, and are simple to service. They hold up to three ounces of fluid for service intervals lapsing each oil change. Includes hardware for installation.