Thermostatically controlled - switches on at 40F and off at 50F. Automatic shut off if water becomes too low. Just remove drain plug and install in drain hole and secure with attached bolts and washers that came with the tank (no hardware is included with de-icer.) Tested to withstand temperatures to 20 below zero. Over 38" of exposed heating element. Fits Rubbermaid tanks. 1500 Watts, 120 volts.
Shipping Restrictions: The following may not be shippable to the specified states: CA