This 400-watt power inverter has a built-in high speed cooling fan and overload protection shuts down the unit if the continuous load exceeds the recommended wattage. With the help of this inverter you can have 115-volt AC power anywhere with a 12-volt DC power supply. It"s basically a DC to AC power converter and is ideal for running computers, cell phones, lights, power tools, television, radios, and CD players in cars, trucks and boats. This inverter protects against damaging current fluctuations and features a low battery alarm to protect the power source battery.