The Duracell Power Inverter 175 offers AC and USB charging convenience from the DC outlet in your car. The inverter converts 12V DC power into AC and USB power so that you can charge up to four devices from the included two AC outlets and two USB ports. Perfect for charging laptops phones iPods and other mobile devices you can simultaneously charge multiple devices up to a total of 175 watts. Additionally the USB ports feature high powered 2.1 Amp rating; the needed power for power-hungry iPads and other mobile electronics.