Mr. Heater Corporation F299811 10,000 BTU Vent Free Radiant Natural Gas Heater, MHVFRD10NG 10,000 BTU Natural Gas heater to heat spaces up to 250 sqaure feet. Radiant heat burner 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. Legs and wall mounting hardware included