So I read the assembly instructions again and also on the website of the seller, the images viewed on item detail. Because I noticed that everywhere a square rail must be pushed into a corresponding holder. For me it is a more rounded shape, so that the rail holds more by stress than they really detained. According to the manual, it should be two L-shaped particles that hold the rail.
After contact with the seller, I have learned that there were changes to the product and the old square rails were replaced by the new rounded. So for me this blind useless because you have to worry every time you touch, the track jumps out. Unfortunately I can not tell you how sensitive it is to the window, because I have to be honest, despite the help of a second person failed to mount it at the window.
It's a pity, because the colors and fabrics are very beautiful, but unfortunately completely useless and thus the product will be returned.