The Eton BoostBloc4000 is a backup battery pack with a 4000mAH lithium ion battery (black) that provides long-lasting reliable power whenever and wherever you need it. Fast and efficient, when fully charged BoostBloc4000 fully charges most smartphones two times, so you're never caught powerless.
With its sleek and elegant design, BoostBloc4000 fits in the palm of your hand. BoostBloc4000 features a Micro-USB DC input to use with most smartphone chargers and a standard USB port for charging any mobile device. An LED charge indicator lets you monitor the battery charge level when you give it a quick shake. Whether you are on a plane or trekking in the woods let BoostBloc4000 provide the power you need to stay fully charged wherever you are.