Noctua NF-A Fan Series Features Roundup @ Neoseeker
 

"The A-series fans are equipped with several features that make for quiet operation by reducing air flow and vibration noise, while other features improve the air flow and pressure efficiency. By applying these and more features across the entire A-series fan line, the end user or network client can be assured of consistency no matter the particular model."


http://www.neoseeker.com/Articles/Ha...nf-a-features/