The K&N 69-8004TTK Typhoon air intake system is a free-flowing, mandrel-bent aluminum tube air induction system designed to fit some Subaru Impreza and WRX models. The restrictive factory air filter and air intake housing are replaced by the K&N Typhoon air intake which is designed to dramatically reduce air flow restriction as it smoothes and straightens air flow. This allows your engine to inhale a larger amount of air than the factory air intake. More air means more usable power and acceleration throughout the engine's RPM range. The 69-8004TTK air intake comes with an ultra-lightweight carbon fiber topped K&N high-flow air filter and a heat shield that installs into the previous air box space. Air is directed through the intake tube into the engine's throttle body for a guaranteed power gain. The intake tube has an attractive textured black finish that's made to last and accommodates the factory mass air sensor. The oversized cone shaped air filter can be used for up to 100,000 miles before servicing is needed depending on driving conditions. This air intake is relatively easy to install usually in 90 minutes or less using existing factory mounting points. The tools needed are a couple of screwdrivers, a ratchet set and some Allen wrenches. Some Typhoon air intakes are not legal for sale or use in California and other states adopting California emission standards while others are CARB exempt and 50 state legal. Check the K&N catalog or website for vehicle applications and specific CARB status for each vehicle and air intake.