AirTechnik CF11920 Cabin Air Filter W/ Activated Carbon Activated Carbon Cabin Air Filters AirTechnik engineers and designs our activated carbon air filters with quality performance durability and cost in mind. AirTechnik cabin air filters keep your vehicle clean smelling fresh and helps with preventing pollutants from circulating in your vehicle to provide a clean and comfortable breathing environment. Cabin air filters are considered the front line of defense and provide a filtering barrier from the hazardous outside particles and elements that may enter the vehicle. Our activated carbon filters can remove dust pollen and other contaminant particles ranging inside from 5 to 100 microns. Our filters also adsorb exhaust pollution and odors from entering the vehicle which provides a clean air breathing environment inside the vehicle.