Mr. Heater, Corporation F299735 30,000 BTU Vent Free Natural Gas Garage Heater, MHVFGH30NGBT 30,000 BTU Natural Gas garage heater to heat spaces up to 750 square feet Blue flame burner for even convection heat. Automatic low oxygen shut-off system (ODS). CSA Certified Operating this heater at altitudes over 4,500 FT above sea level could cause pilot/ODS to shutdown the heater. Theromostat, blower, legs and wall mounting hardware included