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, while its inverted top makes for more filter surface area, resulting in longer service intervals. The air filter is wrapped in reinforced metal providing maximum strength to prevent filter collapse. 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. The Momentum series' patented interface uses a single clamp around the housing to secure the filter to the housing. This simple design allows for easy filter maintenance and replacement.