RK series Repl.filter

K&N claims you get more horsepower from your Twin Cam engine when this extra large "RK series" filter is fitted. Built around the legendary K&N High-Flow Air Filter, the new RK Series assembly includes a billet aluminum cover and back plate that eliminates external breathers and features a built-in, dyno-tuned velocity stack. The result is a significant airflow increase to the engine without sacrificing filtration. This RK Series assembly boasts superior filtration.