The aFe MagnumFORCE Intakes Stage-1 PDS AIS PDS BMW Z4 (E85) 03-05 L6-2.5L M54 is a performance air intake system designed to increase airflow and power for your BMW Z4. It features a Pro 5R air filter with five layers of progressive cotton gauze media for maximum airflow and filtration. The air intake system also includes a high-flow, mandrel-bent aluminum intake tube for improved airflow and a heat shield to protect the filter from engine heat. This intake system is designed to provide improved performance, improved throttle response, and increased power.