Comfort Zone Oil Filled Radiator Heater has 7 warming fins as well as an adjustable thermostat that maintains a constant temperature. Large rolling wheels and a stay cool molded handle makes it easy to move this heater form room to room as needed. The safety features of this heater include a safety tip power cut off switch, safety overheat protection system and a power indicator light. This heater never needs refilling as it is permanently sealed. ETL approved for sale in the US .Comfort Zone® is driven to perfection producing quality products for everyday living.