Mr. Heater MH18B Big Buddy Portable Propane Heater with Big Buddy Carry Case BTU: Adjustable to 4,000, 9,000 or 18,000 BTUs Per Hour HEAT: Heats Up to 450 Square Feet with Hi-Med-Low Heat Settings PROPANE: Runs on Propane Gas SAFE: Oxygen Depletion Sensor (ODS) and tip-over detection system which accounts for low oxygen or accidental falls and automatically turns off the unit, ensuring safe and easy use BUNDLE INCLUDES: Mr. Heater Portable Big Buddy Propane Heater, Mr. Heater Big Buddy Carry Case