Internal 2500 mAh high quality battery cell, while cellphone 100% charged, it will automatically charge the internal battery cell. After a full charge, you will have not only a full charge cellphone but also a backup battery which is able to charge your cellphone to 100% again, without plugging in to a power socket. Customized Indicator light, one shake to activate and display the battery status. When white light always bright indicates the power is enough to charge, when white blinking indicates the power is low. Indicator light not only shows the battery status but also shows the working status. While charging, the indicator light will turn red and blinking. While Finished charging, the indicator light will turn red and always bright. Experienced 10,000 times flex test, anti drop test, to meet the military standards, more durable than usual products. What's in the box 1 x USB intergrated Powerbank