The Just Mobile Gum Max Duo high-performance battery has a charging capacity of 11,200 mAh. It can charge a mobile phone and a tablet at the same time, thanks to its two USB connections. Eight LEDs show the current charge status. This high-performance battery can easily be charged using a standard USB connection. The device has a very elegant aluminium casing, which is protected by a rubber, shock-proof cover for use on the move.