Rexflo 80, 92, 120mm PWM Fans
 

Rexus, ever hear of them? Neither had we until an ambitious
representative had contacted us and sent out three of their Rexflo fans.
Rexus does sell a number of different fans manufactured by Panaflo,
Delta, Sunon, Evercool, and Nidec, but they also maintain the Rexflo
series for fans that run very quiet and use PWM (Pulse Width Modulation)
for reducing noise and managing the fan speed. The fans at hand today
are the Rexflo 80mm, 92mm, and 120mm models.

http://www.phoronix.com/vr.php?view=10291