Wolverine Heaters - Model 40 - 500 Watts - Engine Oil, Reservoir, Biofuel and Hydraulic Fluid Heater - 120 Volts 100% Satisfaction Guarantee - Made in USA - 2 Year Warranty Heats 13 - 27 quarts motor oil / 16 - 32 gallons hydraulic fluid Eliminate cold starts. Faster - easier - hotter engine cranking in cold weather. Tested to -30 degrees. Easy peel & stick application. Installs in minutes, no tools required, no hoses to cut. Apply to flat METAL only. Environmentally Friendly - Reduces start up smoke and harmful emissions