Momentums unique filter-to-housing interface was built to feature the largest air filter possible. This 9 tall 360-degree radial flow air filter features a 5-1/2" flange and our oil-free Pro DRY S media with three layers of synthetic media for maximum convenience. Its progressive layering provides great filtration efficiency and dust holding capacity, while not requiring the use of oils. This media is best suited for street use. Its inverted top makes for more filter surface area, resulting in longer service intervals, while reinforced metal provides maximum strength to prevent filter collapse. Momentums innovative filter-to-housing interface was built to feature the largest air filter possible. Once the system is installed, the air filter can be easily removed from the housing for maintenance by only uninstalling the intake tube. The smooth one-piece sealed housing, constructed of heat-resistant cross-linked polyethylene (XLPE), features our patented (US PAT 9440175) filter-to-housing interface. Its innovative design minimizes the total number of parts, making for an easy installation. A large, clear sight window allows for hassle-free filter inspection, without having to disassemble your system. The housing incorporates factory air scoop inlets, using no additional hardware, and features an optional auxiliary air inlet that pulls in additional air. This system features a high quality, computer-designed, dyno-tuned intake tube to achieve maximum power gains while maintaining a perfect fit. Its XLPE material is heat soak resistant and extremely durable. Stainless-steel clamps and a silicone coupling are used for strength and durability. Momentum HD intakes are designed with fewer parts for a fast and easy installation.