Dymax CO2 Professional Regulator RX-123 is the optimal solution for precise CO2 regulation in both freshwater and saltwater aquariums. Made of lightweight aluminum, this regulator is highly resistant to corrosion, ensuring long-lasting performance in various environments. Its easy set-up process requires no tools to connect to a CO2 cylinder. Key features include high accuracy, hand-tightened design, low heat generation, and a multi-directional solenoid.