Description Videos Reviews AEM Synthetic Air Filter Cleaner loosens and dissolves dirt and grime build up on synthetic filters so they can be rinsed clean with water. This cleaner is perfect for AEM Dryflow air filters and other synthetic air filters. works for all AEM DryFlow Replacement Air Filter for the AEM intake system for the MINI Cooper S (21-699C & 21-721C) 21-2027DK is the direct fit replacement. For easy cleaning instructions, please click on the video tab above! ***Please note - this cannot be exported outside of the USA.*** Official AEM Dryflow® Air Filter Cleaning Instructions Learn how to clean your AEM Dryflow® Air Filter.