Performance Air Filter for Mercedes Benz C Class/E Class/ CLS/ GLK Blue Efficiency Bluetech EnginesOptimized Airflow for Mercedes Benz OM 651 Blue Efficiency & BlueTec Engines Who Its For: Engineered for Mercedes Benz owners running the highly efficient yet often restricted OM 651 diesel powerplant. If youre driving a C Class, E Class, CLS, or GLK and feel that the mid range torque is being held back by a choked off intake, this is the precision upgrade your engine deserves. The Symptom: The factory air filtration system on the Mercedes OM 651