Dyna-Glo IR18NMDG-1 18,000 BTU Natural Gas Infrared Vent Free Wall Heater. All parts and instructions included. This 18000 BTU indoor natural gas heater can heat an area up to 700 square feet. Infrared Technology works by radiating heat -- similar to the sun. LOW-MED-HI control knob offers customization of your heat setting. Not for sale in California or Canada. If you have any questions feel free to ask!