The Perrin drop-in air filter for the Subaru WRX and STI uses a 2-stage foam filtration element to improve airflow in your stock air box; providing improved power and airflow while removing harmful particles from the incoming air. Using a special oil coating, the foam filter catches dirt particles while allowing air to pass unimpeded through the high-flow foam. This filter can be cleaned and re-oiled using the Perrin cleaning kit, sold separately.
WARNING: Cancer and Reproductive Harm
Great product that is great and easy to install.
You can feel the car run smoother and breathe easier.
Gives more noise without changing the whole assembly!
Perrin Drop In Filter Subaru WRX / STI 2008-2018