4 600 BTU heater provides supplemental zone heating for up to 400 square feet to help save you money Instantly switch your existing fireplace to electric when you set this log set on the floor of your fireplace Rolling pulsating realistic log set and ember bed projects flames onto the back of an existing fireplace Overheat protection heater will instantly shut off to prevent overheating Adjustable thermostat allows you to decide the temperature of your room