Blue Flame 20,000 BTU Natural Gas Vent Free heater 20,000 BTU per hour For use with Natural Gas Heats up to 500 sq. Not for use in bathrooms, bedrooms, or recreational vehicles.4,500ft high altitude restriction. Propane cylinder must remain outdoors. Use Supplemental heat in cold rooms, Additions, Sun rooms, Cabins Thermostat Yes Safety Tip-Over Switch No Fuel Type Natural Gas Heat Type Blue Flame Oxygen Depletion Sensor (ODS) Yes High Limit Safety Shut-off (HLS) Yes Indoor Safe Yes Ignition Electronic Hose & Regulator Included No. The item "Mr Heater F299721 Blue Flame 20000 BTU Natural Gas Vent Free Heater" is in sale since Thursday, January 3, 2019. This item is in the category "Business & Industrial\Light Equipment & Tools\Jobsite Heaters". The seller is "jbtool" and is located in Farmington, Michigan. This item can be shipped worldwide.