The D2 replaceable filter is designed for convenience: no cleaning, drying, or re-oiling. It delivers strong airflow while capturing dust and debris. Its advanced fiber construction balances flow and efficiency, with the capability to filter up to 95% of particles, similar to an N95 mask. The result: excellent protection without choking airflow. Just swap it out and go. aFe POWER performance air filters use a rounded, evenly spaced pleat design which allows for more usable filter surface area, providing increased flow and greater dust holding capacity. This aFe POWER performance air filter is constructed with a polyurethane base and top. Unlike other materials that degrade after repeated heat cycles in an engine bay, polyurethane maintains its original molded shape. Utilizing the filter's retention groove, the filter locks into most Stage-2 housings with zero hardware. This simple design allows for easy filter maintenance and replacement.