These Airaid SynthaMax air filters are 100 percent synthetic, non-oiled, and washable. Servicing them is simple--just wash them with a mild household detergent and rinse. Even after several services, the filters look just like new. Their oil-free maintenance makes them the easiest filters to service on the market. Plus, they provide unrivaled filtration efficiency over traditional paper elements. Give your ride better airflow with one of these Airaid SynthaMax air filters.