Subaru STi Performance Panel Air Filter.  Designed as a direct replacement for the standard air filter.

K & N Performance panel Filter.  Designed as a direct replacement for the original panel filter.

A Geniune Subaru panel filter as fitted to all Imprezas. This paper element offers excellent filtration and is edged by a supple rubber seal. This offers excellent sealing properties within the airbox, assembly ensuring only clean air passes into the engine.