Stalwart M600039 is a heater attachment designed to be used with the Stalwart Fan Blower unit. It is not designed to be used as a space heater or for hours of prolonged use. The heater has an internal thermostat to maintain temperatures within normal operating ranges and a thermal fuse for protection against hazardous over-temperature conditions. To operate, attach the heater to the blower outlet and secure the spring clip to the blower catch. Plug the heater power cord into the blower receptacle and turn on the blower first, then turn on the heater with the lighted "On-Off" switch.