Allowing you charge mobile devices without having to be tethered to a plug socket. Each of them fully charges 2.4 times for iPhone X, 3.6 times for iPhone 8 and 2.2 times for Samsung Galaxy S9. (No USB-C output). Each has 2 USB output ports that detect all the connected devices and efficiently distributes the current output up to 5V 2.4A. The USB C and Micro USB ports can fully refill the battery itself in 5 hrs at 5V 2.0A (USB C port is for charging input only, can not be used to charge your device). Thanks to the Li-polymer battery pack, the charger is much safer than any Li-ion charger. Also, it's lighter and slimer that you can easily carry it around, even on airplanes. It feels incredibly compact for a 10000mAh power bank, weighing just 218g and only 14mm thick.