Wolverine Heaters - Model 4.5 - 50 Watts - Engine Oil, Reservoir, Biofuel and Hydraulic Fluid Heater - 120 Volts 100% Satisfaction Guarantee - Made in USA - 2 Year Warranty Heats 1 - 3 quarts motor oil / 1 gallon or less 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