The Tunze CO2 Valve Set 7070.200 is an electronically controlled solenoid valve designed for precise gas control in saltwater reef aquariums. It connects directly to the Tunze SmartController 7000, allowing for automated and accurate regulation of various gases, including CO2 and oxygen, essential for specialized aquarium setups. This solenoid valve conveniently plugs into one of the SmartController's in/out control ports. It includes a Y adapter cable, a thoughtful addition that enables the connection and individual control of another device, such as a light or pump, in-line with the solenoid valve. Its versatility extends beyond CO2 reactors, making it suitable for a wide range of gas applications in the aquarium. This product is ideal for advanced reef aquarists utilizing Tunze SmartController 7000 systems who require precise, automated control over gas delivery for CO2 reactors, oxygenation, or other specialized applications. Its seamless integration and multi-device control capabilities make it a valuable component for optimizing water chemistry and environmental conditions in sophisticated reef tanks.