K&N Drop-In High-Flow Air Filter Subaru 2008-2018 WRX / 2008-2018 STI
K&N's air filters are designed to increase horsepower and acceleration while providing excellent filtration. These filters are custom designed to fit into your existing factory air box. Their drop-in design means adding performance is simple. Simply remove the disposable air filter and replace it with a K&N; there is NEVER any cutting or fitting required.