Unique One-Piece Housing:_x000D_The smooth one-piece sealed housing, constructed of heat-resistant cross-linked polyethylene (XLPE), features our patent-pending 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 utilizes the factory air inlet, using no additional hardware, and features an optional auxiliary air inlet that pulls additional air from the inner fender.