This filter features five layers of pre-oiled cotton gauze media to provide maximum performance. Its progressive layering allows the filter to flow at high levels even when dirty. This media is perfect for street and/or track use. Pro 5R filters are easily recharged with aFe's POWER CLEANER and blue air filter oil. 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. Engineered for efficiency, our patent-pending twist-lock system secures the filter into the housing with a simple twisting motion. This tool-free interface streamlines installation and removal while ensuring a reliable, vibration-resistant seal for consistent performance.