The RFI is an advanced airflow induction built to increase the engine's ability to breath. By replacing the restrictive stock induction, RFI increases horsepower, torque, fuel efficiency, and decreases exhaust gas temperatures. By removing the stock air box, replacing it with a metal heat shield, and using a conical air filter you can maximize the air filter cleaning area and allow the engine to breathe easier and produce more horsepower. All RFI inductions use a lifetime reusable 4" layer cotton gauze filter. This design, combined with deep pleats, make these filters ideal for high performance use.