Advanced FLOW engineering offers you a better choice of oil-free filters: New Pro Dry S synthetic dry-media filters. Pro Dry S filters use a revolutionary two-ply synthetic material that is functionally superior to traditional paper media and single-ply synthetic, and easy to service. Pro Dry S dry-media filters increase airflow providing improved horsepower, torque, and fuel economy with 99.4%* filtration efficiency. Perhaps the greatest benefit of new Pro Dry S filters is the convenience of servicing these oil-free filters.