Cobb Air Filter - Ford Focus ST 2013-2018 / Focus RS 2016-2018COBB High Flow Filters are designed to permit very high flow rates, minimize restriction, maximize filtration and provide a long life filter. It uses proprietary Woven cotton and metal mesh with a precision molded rubber base. WHY? Ford Focus ST Intake filter dual cone 791100 FEATURES Ford High Flow Filter Focus ST 2013 2018, Focus RS 2016 2018 Washable Reusable Cotton Woven Media Precision Molded for Direct Drop In To The Factory Air Box Increased