Hidden breathers are o-ringed at the heads and exit at the mouth of the throttle body/carb to provide efficient engine breathing in a virtually closed loop system, eliminating the need for any external hoses or hardware. Aggressive short length intake tube engineered to significantly increase airflow without sacrificing legroom. Designed to work with factory lowers. Velocity style performance air filter features a built-in inverted top to pull in air from the front and sides, for more performance gaining airflow.