wall heaters are the ideal choice for safe, indoor supplemental heating. This state-of-the-art vent free technology does not require a flue or chimney. These heaters are great for use in your home, cabin, or garage. Since these heaters do not require electricity to operate, they make an excellent choice for everyday heating, and emergency situations when the power goes out. Using infrared heating technology, objects are warmed first similar to how the sun heats feels. This Infrared Wall Heaters burn with 99.9% efficiency, and operates on Propane only. Not for sale in California or Canada. Check your local regulations on installation restrictions and requirements. Propane use requires 100-lb. tank or larger with two-stage adjustable regulator available from local gas company. IRSS18LPT-2P 18,000 BTU Liquid Propane Infrared Vent Free Thermostatic Wall Heater Liquid Propane Ready (Fuel conversion not permitted) Infrared Technology works by radiating heat to warm objects first Similar to the sun Up to 18,000 BTU’s/hr. heats up to 700 sq. ft. Thermostat control knob automatically maintains your ideal heat level No electricity required allows for reliable back-up heating incase of an emergency situation DEPENDABLE Ideal for daily supplemental or emergency use, such as power outagesnbsp; ECONOMICAL Cut heating bills by warming only occupied areasnbsp; COMFORT- Heater automatically adjusts to your desired temperature; just like your home thermostatnbsp; SAFE Built-in oxygen depletion sensor (ODS) immediately shuts down the heater if carbon monoxide or lack of oxygen is detectednbsp; CONVENIENT- One continuous press of the battery assisted igniter makes ignition quick effortlessnbsp; VERSATILE Includes all necessary hardware bracket for wall mountingnbsp; UPGRADEABLE Separately sold optional base legs (WBL100) provide the alternative of floor mounting. Separately sold optional Wall Heater Fan (WHF100) distributes heat in a quiet, yet powerful way.