SureFire GWH30BFNG 30000 BTU Blue Flame Garage Wall Heater, Natural Gas Includes Oxygen Depletion Sensor with automatic shut off safety feature The convection heat warms the air in the room first and then objects; This unit heats up to 1000 Sq Ft Thermostatic control turns blower on and off automatically to keep room at designated temperature No electricity, matches or batteries required to light or run heater; Great during power outages Safe, Clean burning heat