This patented radiant 4,000-18,000 BTU Liquid Propane heater connects directly to two 1 lb. cylinders and is the perfect solution for heating up to 450 sq. ft. An integrated fan increases its heating capacity, blending radiant and convection style heat to give you the best of both worlds. Two swivel regulators allow the ability to adapt usage from disposable cylinders to a remote gas supply with the purchase of a single hose and filter. It also connects directly to a 20lb cylinder with an optional hose that is made of specially designed material that eliminates the need for a fuel filter. To light the unit, simply push and rotate the knob. The built in Piezo sparking mechanism will take care of the rest. With the Oxygen Depletion Sensor (ODS) and accidental tip-over safety shut-off, you can be sure that you will enjoy years of comfortable outdoor safe heat. Its fan operates on 4 D batteries or AC adapter, both sold separately.