K&N Performance Cold Air Intake Kit 63-1114 with Lifetime Filter for Dodge Challenger/Charger, Chrysler 300 5.7L V8 Estimated horsepower gain of 11.77 HP at 4513 RPM Designed to improve throttle response and engine sound Easy to install, usually in 90 minutes or less Replaces entire factory air intake system Not legal for highway use in states adopting California emission regulations