Has met my expectations
I am using this fan for cooling in an av cabinet that houses a yamaha rx-a810 surround sound reciever. The fan is not dead silent but the small amount of noise it does make is a low frequency hum that is barely audible when normal ambient noise is present. Sitting on my couch, which is about 6 feet away from my av cabinet / tv stand, with the fan inside the cabinet and in plain sight it can barely be heard (if at all) with the sytem on mute. The noise the fan make seems to be mainly the noise which is make by the fan blades beating the air, and there is no mechanical noise that i have noticed. As well, i tried running the fan at 4.5v, and the noise level was about the same as running it at 12v.I have very little experience with case fans, but this fan as well seems to move a decent volume of air for the small amount of noise it make. After adding a single fan to my av cabinet, the cabinet temperature dropped by about 8 degrees f.As a word of caution, be careful not to press on the hub or blades, or interrupt the fan motion when it is in operation. From my experiences working in electronic assembly, this tends to damage computer fans and this one seems to be no different. After accidently interupting the fan motion and pushing against one of the blades (in the axial direction), the fan began to make some mechanical noise. Luckily, after about 10 seconds or so, the noise ceased.These fans are rumored to have reliability issues so i will be checking in if i have any problems, but so far i am very satisfied with this purchase (product was purchased from newegg not outletpc. Update:its been over a year and this fan is still going strong, so i am definitely satisfied. And it has plenty of hours of run time under its belt, since it is on whenever my stereo is on, and my stereo is typically on for 4-5 hours a day. One thing to note is its just sitting free within the cabinet, so is not working against a pressure gradient. Still as silent as the day that i bought it.(3/2/17) update:over 3 years and no change - still going strong. Usage is about the same. I'd estimate that i run this fan 2-3 hours a day, on average, and it still runs like the day it was purchased.