Joltz Power Banks J4000B Rechargeable High Capacity 4000 mAh Battery 4000mAh charging capacity provides 10+ hrs. of additional talk time One 5V 1000mA Micro USB charging input and dual output USB ports (output 1 5V 2100mA; output 2 5V 1000mA) 7 adapters for easy compatibility with most all phones Auto shutoff and Overcharge protection Charge time 5 to 6 hours