aFe MagnumFORCE Intakes Stage-2 Si P5R AIS P5R Ford F-150 04-08 V8-5.4LSealed, molded plastic or aluminum cover provides factory style with less intake noise than open systems. Our specially engineered air box openings pull cold air from outside the engine compartment increasing engine efficiency and producing greater performance gain. The cross linked polypropylene rotomolded plastic air box replaces restrictive stock air box and ensures a consistent supply of cold fresh air; built in ram scoop forces cold, outside air