Sentinel now offers (2) CO2 generators, the VCG-27 and theVCG-6. Both units come in either, LP (propane) or NG (Natural Gas) models. All VCGs have advanced safety features which include electronic ignition, dual solenoids and tip-over switches. The VCG-27 has the capacity to produce from 6 to 27 cubic feet of CO2 per hour simply by turning selector valves. The variable CO2 output allows the user to select the correct amount of CO2 for their area. The VCG-6 shares the same features of the larger VCG-27 but it is aimed at smaller set-ups and for people on a budget. All VCG units come complete with clean burning, pre-installed brass burners, the appropriate regulator/hose and offer a 3 year warranty. For more information visit www.growgps.com