3 usb power ports charge up to 3 mobile devices simultaneously through just one wall socket. provides standard usb 5v at up to 3.1a (max). phone can be used during charging. lightweight and easy to carry. short circuit, overload, over-voltage protection. plug and play. blue led indicator light. compatible with ipad, iphones and ipod and other smart phones suitable for home and travel use. great for charging cell phones, cameras, mp3 players.