Built around an LG Lithium rechargeable battery pack, this power pack has a charged capacity of 15,000 mAh (which is quite large), and provides charging power through two 5v 2.4a USB sockets. You can charge two devices (phones, tablets, etc) simultaneously. It recharges using a USB micro cable (included).
This is a very handy device to have, no matter whether you are on a trip or in a long meeting and your phone battery gets low. You charge your device directly from this power pack, no AC outlet required. This power pack is well built and will be kept in my briefcase, for use when I need it. I think it would be a good idea to recharge this device after each use and probably at least monthly.
It comes complete with the power pack, a charging cable, storage pouch, and owner instructions.