The EW3990 150W Power Inverter 12V to 230V with 2.1A USB port provides power for your devices when you are on the road. Charge your USB devices via the built-in USB port. The EW3990 is equipped with fourfold protection: under and over voltage-, overload-, overheat- and short-circuit protection. Connect the inverter easily to your car's cigarette lighter. Did you know that the EW3990 fits into the cup holder of your car?