Air filter element Washable and reusable high-efficiency air filter Thanks to FCd (Full Contour design) technology, the entire surface of the air filter box intake can be used as a filter medium. This increases the filter area by 20-80%, increases airflow, and improves engine power. The increased airflow also reduces fuel consumption. The DNA filter medium consists of four layers of special DNA cotton fabric, sandwiched between 2 plastic-coated aluminum meshes. These are held together by two aluminum wire meshes. The special pleating technique of the filter medium increases the inner radius and provides more filtration. Maintenance advice: The filter should ideally be cleaned and oiled once a year or every 15,000 - 30,000 km. The filter must not be used without being oiled, as the filter medium will otherwise not provide optimal filtration performance. Only DNA service products may be used for cleaning and oiling!