K&N 57S-4521 Performance Air Intake System designed to dramatically reduce air flow restriction as well as smooth and straighten air flow. Replacing the restrictive factory air filter and air box allows your engine to inhale more air than with the factory air filter assembly. More air means more usable power and acceleration throughout the engine's RPM range. A fully enclosed injection molded air box connects to the factory air intake hose. The removable lid provides easy access to the filter when cleaning is required. This performance air box is relatively easy to install. The required tools are commonly available and it uses the previous air box space. These air box systems are built to last for the life of your vehicle and they're backed by K and N's No-Hassle Lifetime Limited Warranty.