The 3X Industrial cartridge is recommended for ALL TYPES OF ORGANIC ODORS! For use with HVAC systems, high-velocity blowers, fans, or where air can move through the cartridge to release the non-toxic, odor-neutralizing dry vapor. Membrane contains safe, natural, essential oils. Has rotating end caps. Treats areas up to 20,000 cu. ft. Cartridge life varies from 270 hours to 60 days, depending on application.