This CO2 regulator is specifically designed for CO2 generator system. Install this CO2 pressure regulator need a wrench. Place the washer ensure a tight seal. Replace washers regularly recommended. It is easy, safe and economical. Features: Be made of stainless steel. It is strong, durable and efficient. Well-sealed caps, leak-proof, non-deformed, never loose. Professional pressure gauge for pressure watching. High pressure gauge shows cylinder pressure, low pressure gauge shows output pressure. Large double pressure gauge: Safe and with long service life, regulated output, stable operation. Pressure reducing valve: High voltage input constant voltage output 3KG pressure. Solenoid valve: To control the on and off of CO2 generator system using with a timer(not included). 100-240V wide voltage input, DC 12V output, the solenoid valve is 12V noiseless version. Bubble counter with check valve: Flow-rate of CO2 gas indication device and prevent water flow back into the bottle. Precision fine-tuning, achieving 2-3 seconds 1 bubble. Install this CO2 pressure regulator need a wrench. Place the washer ensure a tight seal. Replace washers regularly. Any problem, please contact our store without hesitation. Honor to serve you Specification: Name: Aquarium CO2 regulator Main material: Stainless steel Color: Silver Optional interface type: W21.8/CGA320/G5/8 Input voltage: 110V (US); 220V (EU) Output voltage: 12V Size: 16.9*15cm Package Information: Package size: 24 * 22.5 * 13cm Package weight: 595g Gift Box Packaging Package List: 1* Aquarium CO2 regulator 1* Wrench 1* Instruction manual 1* Other parts