This device does both tanks. I have tank penetration kits for DIY installation. It's on a timed cycle where it feeds ozone rich air into the tanks, which is rapidly broken down in the presence of the wastewater. No odors from the vents, so odors cannot find their way back into the coach. Powered by 12 volt DC less than 7 amps. Not only does it remove odors it also kills most all pathogens in the waste making it safe to handle while dumping. I also make air purifying/sanitizing device which do not produce ozone to rid the coach of odors from cooking, pets, smoking and destroys airborne pathogens such as viruses.