Steeda's Patented Billet Aluminum intake spacer is designed specifically for the V8 S197 Mustang. Made from Billet 6061 aluminum it is designed to give you more plenum volume for increased horsepower. The swirl design helps promote airflow by breaking the surface tension of the incoming air. Accourding to Steeda An increase of horsepower and fuel milage should be seen with this part. Kit includes instructions, gaskets and mounting hardware.