Faulty touch.

Packaging is impeccable, comes with tools, glue, ect. Some tutorials are easily available in video.
By cons, after 20 min of hard, first test the touch reacts, but evil.
After downloading a test application, we can see that on the lower part, the touch is good, but not over the top. (It is accurate to 2cm around, so if not finger is placed in the right place, it counts as double-pressed (once 1cm below, once 1cm above.) Thus, you can not click precisely.)
After re-20min, I withdraw it and returns it to Amazon (repayment;) and I order a second.
This time, I test it before (without stacking) and I have exactly the same concerns (returns in progress).
Too bad, because otherwise it was perfect.