The RAZORXtra rechargeable 9000mAh battery is up to 5x Extra battery. It has a 3.4A input and 2 USB ports deliver shared 3.4A output. It can be recharged via micro-USB port. It has an ultra-thin design with an anodized aluminum finish. It also has a four-light LED battery indicator, which you shake to check battery level. 1) Smart-sense: ensures complete device compatibility, 2) Power-stay: maintains battery power for up to 1 year, 3) Max-power: maximum power transfer from powerbank (charger) to device, 4) High-density battery: the smallest and lightest powerbank, 5) Safe-cell: provides the highest level of battery safety.