Features. No flame flue or chimney. No electrical drain or battery connection make it the ideal solution for boon docking and dry camping. Silent operation - No fan or blower noise. Self-generating piezo starter. 100 safety shut-off valve. Use inside RV as portable unit or permanently mounted. Can also be used outdoors as portable unit. Safe for operation at altitudes up to 12000 feet. Adjustable from 3200 to 6000 btuhr. Will heat up to 230 sq. Ft.. For use in vented areas only