Big Buddy New Version Heater - With three heat settings of 4,000 BTUs, 9,000 BTUs and 18,000 BTUs this small heater can heat up to 400 square feet, supplying 6 to 12 hours of heat from 2 - 1lbs propane cylinders or 120 (from 1 - 20lbs cylinder) to 240 hours of heat (from 2 - 20lbs cylinders) using the optional hose attachments (not included). It has a heat-circulating fan, a low oxygen sensor shut off, and it also includes a blower fan that is powered by 4 D-cell batteries (not included). The storage bay in the bottom accommodates up to 12 feet of hose. Approved for temporary indoor and outdoor use. Dimensions: 17-1/2 inch H x 17 inch W x 10 inch D.