The Mr. Heater 6 000 - 18 000 BTU portable cabinet heater is ideal for all outdoor applications. It requires no electricity and is whisper quiet. With clean odor-free operation an oxygen depletion sensor (ODS) and accidental tip-over safety shut-off you ll enjoy years of comfortable safe heat. Heats up to 450 sq ft and has three heat settings - 6 000 12 000 and 18 000 BTUs. To operate just connect to a 20 lb propane tank using the included hose and regulator stow the tank in the cabinet behind the burner then simply push and rotate the knob to pilot and the piezo sparking mechanism will take care of the rest while you enjoy quiet radiant warmth. Operates up to 72 hours on a 20 lb propane tank on low setting and is CSA certified.