Fans are good and solid processed. Optically also in top with the special lighting and are now running smoothly for about 1 year. They are intended in a silent system with almost durgehend "mesh" as a front / TOP / Back whereby the LED optics comes great advantage. Unfortunately, they are much too loud for me a "Quiet Edition" and I had to turn down much (max 1000Umin) - at full load is not "quiet" to hear of the slightest. I have therefore under load insufficient air delivery or the system is too loud.
I have a parallel Silentwing of beQuiet - this is virtually inaudible. And even at full load at 1 m distance noise heard just as easy. The price difference there are no 10, which I then shows too few for the volume difference in price. For me, therefore, only 3 out of 5 stars.
