These Airaid intake systems are designed to work with today's vehicle technology. They increase the amount of air entering your intake and therefore increase horsepower. You will get an estimated 20% increase of airflow and as much as 18HP. There intake tube is a 3" design and is much less restrictive than the factories setup. They come with splash shields that will protect the filter from engine heat and the elements. The filters are washable, reusable, and will last for the life of the vehicle. The kits come with everything you need to install them and there is no fabrication required. Applications: 2005-2007 Ford F-150 STX 4.6L 2005-2007 Ford F-150 XL 4.6L 2004 Ford F-150 4.6L 2005-2007 Ford F150 XLT 4.6L