K&N Nissan Titan & Armada 5.6L - V8 2004 Drop In Air FilterK&N's replacement air filters are designed to increase horsepower and acceleration while providing excellent filtration. We make over 1,200 different replacement air filters for the majority of vehicles on the road. These filters are washable and reusable and are custom designed to fit into your existing factory air box. Their drop in design means adding performance is simple. With most vehicles you simply remove the disposable air filter and replace