The VWR Intake filter is constructed from three layer open-cell polyurethane form, which gives a high level of filtration to protect the engine from contaminants in the air, while not greatly restricting airflow. This same filter material is used by F1 teams around the world due to it's excellent filtration and airflow properties. In VWR's experience, cheaper foam filter materials are unable to deliver the same flow and filtration meaning a compromise for your engine.