NEEBOOL 10400mAh High-capacity UltraThin Portable External Power Bank Battery Charger with Dual usb Travel Charger for Cellphones and Tablets (black) Built-in 10400mAh high capacity rechargeable Li-Ion battery.can keep your mobile devices running all Simple Compact, Portable&fashionable design; High security with charging and discharging control, short circuit protection With dual USB output, charge 2 devices simultaneously Easy to hold in hand or put into bag/pocket.