Features a billet aluminum backing plate with hidden integrated breather system and a plexiglass outer cover, Snap-in velocity stack for improved airflow, High-flow air filter is reusable; just clean and re-oil, Dyno-developed and tested, Delivers an impressive ~8HP power boost over stock, Includes mounting hardware and 1 rain sock, Made in the USA, Recirculates head pressure back into the throttle body, aligning with the stock Harley-Davidson air cleaner setup. For those seeking to vent the head pressure externally, our external breather kit is also available for purchase.