ROMOSS Sense 4S?11000mAh Portable External Power Bank Battery Charger Pack Recharger Power Supply Station Dual-USB Port Fast Charging for iPhone iPad Samsung HTC Huawei Android Cell Phone and more Fast Charging And Efficient Output: fast self-charging IC technology saves half time to fuel up the power bank, power output conversion rate improved to 85% ensuring 4 full charges on iPhone 5s Dual USB and Charge while Discharge: charge 2 mobile devices at the same time and can be charged and discharge simultaneously Compatible and Smart: automatically adjusts output based on the connected device, compatible with all popular smartphones and tablets Compact and Enduring: simple and elegant look with portable size, dormant when unused to avoid any power waste LED indication for battery status