This blue flame 20,000 Btu liquid propane vent-free heater is the ideal supplemental heating solution even on the coldest days. This heater is conveniently equipped with a thermostat for great 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.