Armor All FRESHfx Vent & Duct Cleaner Odor Neutralizer is created specifically for automotive HVAC (Heating, Ventilation, Air Conditioning) systems. Armor All FRESHfx Vent & Duct Cleaner Odor Neutralizers special formula allows you to treat vents, ductwork, evaporator core and drain pan area, helping to eliminate a variety of odors caused by mold and mildew. It also cleans by removing light dirt that resides in ductwork and dirt and dust that sits on vent surfaces. NOT A MASK OR COVER-UP: A formula that stops and neutralizes odors!