Cell Phone Battery Backup Dual USB Portable External Extended Battery Pack Portable Power Bank with 20,000 mAh (twice the power of others) Portable Charger Battery with Dual USB Charging Ports for Charging Multiple Devices. Battery Pack for Charging All Mobile Smart Phones and Tablets. Get One for Home Emergency and Several for Use Where Charging Your Portable Devices Are Not Possible From a Wall Outlet. (blue) 20,000 mAh power for charging multiple devices multiple times. Charging cable for all cell phones and tablets. Battery can be charged from 110v wall outlet or from any usb port in vehicle or lap top. Used by bikers, hikers, and campers to keep their devices charged in case of emergencies. College students can recharge tablet or phone in class. Great to recharge cell phone when playing Pokeman