100% Manufacturer by Xiaomi， you may purchase with confidence. The Power Bank is built with safety， protection and efficiency in mind. Designed by Texas Instruments， the USB smart-control and power source chipsets are strengthened by nine layers of circuit chipset protection. Mi Power Bank automatically adjusts its output level based on the connected device. Easily charge smartphones and tablets from Mi， Apple， Samsung， HTC， Google and BlackBerry， as well as a variety of digital cameras and handheld gaming devices. The one-piece carved aluminum casing ensures structural rigidity. Tested to withstand 5，000 micro USB insertion/removal cycles and 1，500 USB insertion/removal cycles. Simple design， compact and easy to take along for trip， ideal gift for family and friend， or yourself. 1 year local warranty. Product specification Lithium-ion rechargeable cell Input Voltage: DC 5.0V Output Voltage: DC 5.1V Input current: 2000mA(TYP) Output current: 2100mA(TYP) Rated capacity: 3.75V/16000mAh(TYP) Charging time 9 hrs with 5V/2A plug and standard cable 14.5 hrs with 5V/1A plug and standard cable Remarks Each of the two ports supports 5.1V/2.1A output When both ports are used simultaneously， maximum output is 5.1V/3.6A Size: 145*60.4*22mm Load detection Auto-detect the plug-in and plug-out of devices Safety Supports protection from over-voltage (input and output)， over-current (input and output)， short circuit， over-charge， over-discharge， and battery Positive Temperature Coefficient (PTC). Out of power protection Awake once pluged to the charger Charging temperature 0℃-45℃ (TYP) Discharging temperature Initial: -10℃~+50℃(TYP) Continuous: -20℃~+60℃(TYP) Weight:350g