Unfortunately, he has already begun the first installation of an edge when I wanted to screw it to the housing. Maybe I wanted to screw it firmly to him, however, may not happen to you. So be very careful when installing, as the material does not seem to be as stable. For me it is hard to hear, as I have already installed some bigger fan.
He is, however Bereis kaputtgegangen the first installation, there is only 2 stars.