With the output to heat up to 400 square feet for up to 120 hours on a bulk cylinder, this powerful little heater is ideal for taking the chill off almost any place you need extra warmth. And because its equipped with a low-oxygen shut-off pilot safety, it can be used safely in tents, blinds, ice shacks and other enclosed areas. Three settings let you adjust the heat from 4,000, to 9,000 or 18,000 BTUs/hr. Two one-pound propane cylinders provide from 6 to 12 hours of radiant and convection heat for maximum efficiency. It even includes a blower fan, powered by four D-cell batteries (batteries not included) so you can direct warmed air into chilly corners or other hard-to-heat areas. A storage bay accommodates up to 12 feet of hose, sold separately, for use with bulk propane cylinders. Recommended for use at altitudes below 7,000 feet. Cannot be sold in Massachusetts and Canada. Dimensions: 17-1/2H x 17W x 10D. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Heaters.