FZONE Pro Series Aquarium Dual Stage CO2 Regulator Adjustable Output Pressure with DC Solenoid and Integrated High Precision Needle Valve and Bubble Counter - Dual stage construction & adjustable output pressure. Dual stage construction provides stable output pressure regardless of how much CO2 gas remains inside the CO2 cylinder, eliminating unpredictable catastrophes such as an end-of-tank-dump (EoTD). The output pressure is adjustable from 0-65 PSI based on customers different needs. - Modular manifold block design. Two manifold blocks are included. Each block comes with its own high-precision needle valve and can be operated independently. You may use one block for one aquarium or use both for two aquariums. - Safety and precision in mind. Our regulator has a built-in safety valve. It will open automatically to release the pressure when it exceeds 100 PSI. The integrated needle valve is precise. The CO2 output can be adjusted to as low as 1 bubble every 3 seconds. - Solenoid runs on 12V DC instead of conventional 120V AC. This regulator adapts to 12V DC, which is more stable and consumes less power. The solenoid is safe to touch and is very quiet. This solenoid is designed to work with an automatic timer. - Attention. Suitable for North American CO2 cylinder with CGA320 adapter! Installation tools are included.