This is a charging cable that charges through a USB 2.0 or 1.1 port. It is a must if you don't have a surge supressor strip at an internet cafe' with only your notebook computer or your travel charger doesn't have room to fit in the wall socket when your notebook computer is plugged in! It even works when your computer isn't on! Also compatible with a USB 2.0 or 1.1 hub. You can also use it with a desktop USB 2.0 or 1.1 port.