K & N Filters 77-2557KP 04-05 F150 4.6 FIPK Guaranteed to increase horsepower // Designed to improve throttle response and engine sound Free-flowing aluminum tube // Replaces entire factory air intake system Lasts up to 100,000 miles before service is required (depending on driving conditions) Easy to install, usually in 90 minutes or less Washable and reusable lifetime air filter // K&N Million Mile Limited Warranty