Paulin Products Inc Tough Pup 8,000 BTU Propane Radiant Heater #7500 4,000/8,0000 Btu portable heater For indoor use; heats up to 250 square feet Unique on/off gas flow valve and low-oxygen shutoff for complete safety Connects to 1-pound cylinder; optional hose assembly for bulk tanks (not included) Cylinders larger than 1-pound should not be used in enclosed spaces; lifetime warranty