Class fan, ... with one caveat.

Even at low speed, you make a nice strong blue. Also no problems with a low budget fan control as they start reliably even with low starting voltage. The capacity is sufficient and operation, at slightly reduced voltage by a fan controller, really quiet!

So far so good. The common limitation of hanging, extinguishing installation in the lid of my housing. Four of the fans give a clearly perceptible Lagerklackern of itself. After testing of all the fans, I just found two that are ok. One shows no noise, the second minimal.

But that only affects this mounting direction. In normal operation, all fans run smoothly and quietly, and are really worth the money!