JR Products HTH-A Dual Voltage RV Holding Tank HeaterProtect your fresh water tank or septic tank from freezing with this holding tank heater. This is a simple way to start preparing your RV for the winter season. It is dual voltage ready for 12V or 110V, and is thermostatically controlled at 34 degrees F. KEY FEATURES Used on either fresh water or septic tank Dual voltage ready for 12V and 110V applications Thermostatically controlled and active at 34 F Foil covered heater is 30 x 13 with 24 ground