Installation is simple with the "rubber nipples" which will probably minimize the vibrations actually explained everything by themselves. The fans sit so Bombenfest wobbling excluded! But I have used a small pliers to pull them hard (probably had to greasy fingers). The direction in which the fan-ventilated is indicated by an arrow on the fan that was not so in my old.
But now the most important thing they are practically inaudible from the closed case! Every little noise drowns out the fan immediately! My power supply and my graphics card remain in the desktop operating silently because their fans run only under load so I hear while surfing just the two Sharkoon fan and as I said just Extremely quiet. A whirring or buzzing noise is me not even noticed.
Of the rubber nipples there is in reserve and screws are still in the process.
Conclusion: Great very quiet fan in my opinion should be sufficient for the vast majority of PC.