be quiet! Pure Wings 2 & Silent Wings 2 Case Fans Review @ Neoseeker
 

"By adding extra fan blades with a unique foil design to reduce air turbulence and therefore noise, then using long life bearings to give the user peace of mind with a slower rpm, the be quiet! fans are an excellent choice for any computer enthusiast."

http://www.neoseeker.com/Articles/Ha...ilent_wings_2/