The manual is in English, but this is not a concern because it is easy to use. Simply pressing the button on the front to turn on the battery, a long press to turn it off and two pressures to turn on or turn off the lamp on the top. It is responsible directly to the mains via the supplied USB cable and PC. It is secured and protected against overvoltage and short circuit. On the front, there are 3 small LEDs that indicate the progress and the charge level of the battery.
With a single charge, I could totally recharged my iPhone 4 about 2:30; I could also use it with my tablet, my Huawei, my BOSS helmet and even the small pilot giraffe my son ...
I find it very pretty and elegant with its rounded edges, its color and its dark gray top orange, while aluminum alloy, it is not very heavy (about 200 g) and does not take more space in my bag my lipstick.
In conclusion: It is a very good battery backup that does not leave my bag. My essential ... 2 in 1 battery and flashlight !! Very good quality product for a reasonable price.