Used Mr. Heater Vent-free blue flame 30K BTU NATURAL GAS heater, heats about 1,000 sq. feet. Heater works great been used as supplemental heat in bonus room till I got a mini split. Unit has push-button electric spark for pilot light ignition and optional built-in fan(plug in standard wall outlet) with digital temperature LED readout. I do not have owners manual or paperwork. This heater is for NATURAL GAS ONLY!!! Will not work on propane or other gases.