These very complete High-Performance air cleaner kits feature an aluminum backing plate with an integrated velocity stack, providing a better airflow for increased horsepower and torque through the entire RPM range. Everything needed to install these kits on your bike is included, only the air cleaner cover must be ordered separately in your choice of black or chrome. Cover is 10 3/8" (26 cm) long, 8" high (20 cm) and 3" (7.5 cm) deep. Kits include a low restriction air cleaner element, chrome air cleaner support bracket, crank vent hoses and adapters, gaskets, and all required mounting hardware. Available for Evolution Sportster, Evolution Big Twin, and Twin Cam models.