Propane Gas Vent Free Infrared Gas Space Heater With Blower 18,000 BTU, T Stat Control Value:each Omnidirectional 360° light illuminates large GlueCore Omnidirectional 360° light illuminates large areas both indoor and outdoor A: It locks with a push button from the inside and can be unlocked from the outside with the included pin key for emergencies Thermostat Control The built in thermostat automatically cycles the heater on and off to maintain your desired heat setting This radiant heater features the latest advancement in vent free infrared plaque burner design which uses larger plaques to provide more heat per plaque