K&N Mercedes Benz A/B/CLA Class Performance Air Intake SystemThe K&N Performance Airbox is designed to dramatically reduce air flow restriction as well as smooth and straighten air flow. Replacing the restrictive factory air filter and air box allows your engine to inhale more air than with the factory air filter assembly. More air means more usable power and acceleration throughout the engine's RPM range. A fully enclosed injection molded air box connects to the factory air intake hose. The removable lid