The Mr. Heater Big Buddy Portable Heater is a patented, radiant, 4,000-18,000 BTU liquid propane heater that connects directly to two 1 lb. cylinders and is the perfect solution for heating enclosed spaces like cabins up to 450 sq. ft. Two swivel regulators give you the ability to adapt usage from disposable cylinders to a remote gas supply with the purchase of a single hose and 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 indoor safe heat.Features4,000, 9,000, or 18,000 BTU per hourFor use with propane gasHeats up to 450 sq. ft.Single control start knobHi-Med-Low heat settingsSwivel regulatorsAutomatic low oxygen shut-off system (ODS)Accidental tip-over safety shut-offConnects to two 1 lb. cylindersConnects to a 20 lb. cylinder with optional hose