Our holding tank heating element is an easy and practical way to winterize your RV or Trailers tanks. They can be used on either fresh or septic tanks. It is dual voltage ready for both 12-volt and 110-volt applications. These elements are thermostatically controlled and activate at approximately 34° Fahrenheit to stop the contents of your tank from freezing. The element is 30" x 13" and is a foil covered heater. It comes with a 24" ground wire for safety, 6' of 120-volt wiring for easy installation. Each heater draws approximately 1-Amp A.C. and 10-Amps D.C. current when in use. Multiple elements can be used where needed for tank coverage. 1- Heater for 15 gallons, 2- Heaters for 30 gallons, 3-Heaters for 45 gallons.