Mr. Heater Corporation F299820 18,000 BTU Vent Free Radiant Propane Heater, MHVFRD20LPT 18,000 BTU Liquid Propane heater to heat spaces up to 500 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. Theromostat, legs and wall mounting hardware included