Gen-2 Carbon Dioxide Generator. This propane powered co2 generator comes with five burners and its output is 15 cubic feet per hour. Three more burners may be added to increase the co2 output to 25 cubic feet per hour. Burners may be added one at a time to increase co2 output. Each burner will emit 3.1 cubic feet of co2 per hour. Safety features include a tip-over switch and main burner may not be ignited while lighting the pilot flame. Top does not get overheated like other brands. Ask if Green Air Products have these features. They Donít. This model is every bit as good as if not better in every function than its closest competitor. Shop and compare. Gen 1 shown.