This liquid propane convection heater utilizes the natural act of warm air rising to quickly heat up garages, barns and workshops. Just attach it to a propane tank and enjoy the comforts of a toasty warm job site. (20,000 and 80,000 BTU units attach to 20 lb. tanks; 200,000 BTU unit attaches to a 100 lb. minimum tank.) Equipped with a thermoelectric safety valve to shut off gas flow if the flame ever goes out.