Designed specifically for use in high-altitude locations above 4,500 feet, the Blueprint Controllers® CO2 Generator BCGL-4H features four preinstalled brass burners that generate 8.7 cubic feet per hour of CO2 using liquid propane. The generator includes plugs to reduce the number of active burners, making it easy to reduce the CO2 and heat output to suit a smaller growing space. It features electronic ignition and solenoid valve operation, which eliminate an open pilot flame and provide safe, reliable starts. A safety tip-over switch automatically stops gas supply to the burners if the unit is not upright. This unit includes a gas regulator, 12-foot hose, hanging hardware and a three-year warranty. It measures 16 inches by 10.5 inches by 21 inches.