Stay warm this winter with this 12 volt heater. Heater features a 3 position switch from heat to fan only. Rotate top knob to adjust the fan speed to your preference. Easy to install and complete with installation instructions. Positive cable is fused.The 12 Volt Direct Wire Ceramic Heater is the largest, most powerful 12 volt DC heater available. 300 watts of power ensures plenty of heat where you need it. Directly connects to your vehicle battery.