Car inverter with 4000W power and modified sine wave output. It converts the 12V DC power from the car or boat battery to 220V AC power, allowing you to power all devices that require 220 Volts wherever you want. 

It is usually connected either with a double power cable (positive and negative) to the battery terminals or directly to the car's cigarette lighter. Then, you can connect the desired devices to the sockets it provides.