Indoor safe propane heater. Radiant heater provides safe heat for chilly garages, tents, patios, porches, cabins, etc. It has been designed and approved also for indoor use. Automatic low-oxygen shutoff system. Uses 1 lb. or 20 lb. propane cylinder with optional hose connection model. Free standing or wall mount. Quiet, odor-free, lightweight, portable. Easy-to-carry. 3 to 6 hour run time. Low oxygen sensor prohibits use at altitude above 7000'. Fuel cylinders not included.