Noiseblocker introduces 40 and 60 millimeter fans that are intended for compact PCs.
40 and 60 millimeter fans usually are intended for industrial usage and thus have quite loud bearings and are turning at high speeds. Noiseblocker offers four models of the Black Silent series which is supposed to cool compact (ITX) systems in a quiet way. The specifications of the Black Silent series:
Air flow rate
Black Silent XM1
Black Silent XM2
Black Silent XR1
Black Silent XR2
Noiseblocker says that the Black Silent series is available from now on.