The HD RKSport Ram Air/Extractor Hood will fit for both the Gas Engine Model as well as the Diesel Engine Model.  It is designed to collect and "ram" air into the throttle body, increasing horsepower, throttle response and improving fuel economy while minimizing drag.  The Extractor portion will help keep your engine bay cooler by drawing hot air out.  With our unique baffled desing, outside elements such as rain & debris are kept out of the engine compartment.