What silence! Exactly what I expected ventilos buying these to replace my Coolermaster RC 650 housing that were small enough désagrable noise. They are certainly a little expensive but the cost valen. One small problem: I have ordered 2 and in one of the boxes were missing the little bag of 4 screws. Not matter because in the end I used the silicone materials, but it's job ... And Noctua could choose other colors to its range ...