HKS recommends changing the air filter every 5,000 miles on your HKS suction to keep the filtering efficiency at an optimal level. The HKS Super Mega flow element is a 2-layer, dual density, wet-type polyurethane filter that uses an impregnated viscid fluid to attract and stop damaging dirt particles from entering your engine. This bonded fluid allows use of a larger pore design for maximum airflow without sacrificing filtration. Standard in the Super Mega Flow is the HKS trademark green filter element. Replacement filter elements are available in a variety of colors. Fits The Lancer Evolution HKS Suction Intake