The Brunton Metal 4400 is a compact, 4400mAh rechargeable battery pack. It features dual USB 2.0 and Micro USB output ports to connect most small electronic devices using their USB charging cables. The internal battery is charged using an integrated USB cable that can be connected to any USB port, a USB/AC plug or Brunton's Solaris 4 USB solar charger. The Metal 4400 power station is ideal for charging smart phones, MP3 players, cameras, radios or most other small electronic devices. The compact and lightweight pocket reactor is only 2.1 inches. There is a power button and LEDs show if it is activated, charging, and the available power