This Mr. Heater Blue Flame 20,000 BTU Natural Gas Vent Free heater is the perfect supplemental heating solution even on the coldest days. This heater is conveniently equipped with a thermostat for superior control of the temperature in your space. Also, with a battery powered electronic ignition, starting it is a breeze-battery included. This unit can be permanently mounted to the wall or securely fastened to the floor with included mounting brackets and fasteners. A clean burning blue flame tube burner uses the natural convection of the burn to circulate warm comfortable air. With a factory standard Oxygen Depletion Sensor (ODS), rest assured this heater will provide you with years of comfortable and safe heat.