Proheat Heavy Duty Fluid Reservoir Heater Model 150-12 150 Watts, 12 Amp, 12 Volts DC Ideal for Oil Pans up to 1 Gallon of Fluid (3.5 Litres) and 5+ Gallons of Hydraulic Oil. This heater is designed for Hydraulic applications. Also for use on oil pans where 120v may not be available. 4 X 4 X .08"