G.A.S Pro-Leaf CO2 Regulator — Bottled CO2 DeliveryG. A. S Pro Leaf CO2 Regulator Bottled CO2 Delivery System The easiest way to add CO2 supplementation to a grow room the Pro Leaf Regulator fits directly onto a standard CO2 gas cylinder and uses a solenoid valve to release gas in controlled bursts. Controlled by the Pro Leaf Controller (sold separately), it delivers exactly the CO2 ppm you've set, and stops when the target's hit. Why growers choose the Pro Leaf CO2 Regulator: Direct CO2 cylinder