This is a great cooling thermostat with a heavy duty 120 Volt 3 prong piggyback power cord. The thermostat has a gas filled coil for great reliability. It has an accuracy of plus or minus 2 degrees Fahrenheit. The thermostat turns fans ON when the temperature has reached 4 degrees above set point and turns fans OFF at 3 degrees below set point. Simply plug your fan into the thermostat's cord, set the dial and your done. The temperature can be set for anywhere between 40 to 110 degrees Fahrenheit.