Indeed, the burden of 2.1 mAh allows fast charging. It also will run almost all the devices charging via USB.
With a capacity of 3000mAH autonomy is more than enough during the day.
It has a small on / off button that can check the charge level and fill a flashlight function very suitable LED (LED 4).
It comes with two connection cables: one for charging and one connection (non-Apple).
Really a very good product