The Muc-Off Biodegradable Air Filter Cleaner is a state of the art, professional strength biodegradable cleaner which cleans and cares for your filter. It rapidly breaks down the stickiest of oils, grease and the nastiest grime on all foam air filters. It’s the hassle-free way to rapidly clean your foam filter and ensure you maximise your engine's horsepower. The unique combination of active ingredients is formulated to rip through dirt and oil without damaging the foam or glue.