This K&N drop-in High-Flow air filter is a washable, reusable replacement engineered to improve airflow and help increase horsepower while protecting the engine. It installs in the factory airbox and is covered by K&N's No-Hassle Lifetime Limited Warranty. The listing includes fitment for various Subaru applications such as Outback (2003–2010), Legacy (2005–2010), Impreza (2007–2010) and Forester (2008–2010).
K&N 05-08 LGT / 08-11 WRX / STi Drop In Air Filter