AeroCool Shark 120mm Red Cooling Fan

Runs good in 12V mode but in 7V mode you can't even hear it with your ear up to it. Still moves air and is perfect for front case fan. Lights are perfect .. bright but not too bright .. creates a faint white glow which I really like. After trying and returning a few other brands that claimed to be quiet I can highly recommend this Aerocool fan.

So 26 dB is supposed to be just slightly quieter than a whisper (30 dB I believe) but this thing is definitely noisy when plugged into a molex cable. I suppose the term whisper is subjective even with numbers. The airflow is great but it blows outward, less forward and more radially is the best way to describe it. And since it was mounted on the side panel it wasn't blowing directly on my graphics card. Not wanting to have this fan go to waste I instead moved it to the back as my exhaust fan where it became much quieter thanks to PWM, and moved my Cooler Master 120mm Red LED Case Fan - (R4-L2R-20CR-GP) to the side. The results were better than I could have expected. When playing battlefield 3 for a few hours my temps were very low, my card never getting above 78, and whats more the sound from my computer never changing. Even with the gpu fan going it never got much louder than idle. Using my Sound Meter app, my computer is at 19 dB at idle and I will have to measure it some other time when playing a game though it was quieter than just having this fan on the side panel. I deduct one star not only for the noise (though that's less the card and more not understanding what 26 dB sounds like) and for the not quite forward airflow. As far as the red led. It's red, it's a light, looks nice.EDIT: After playing Battlefield for hours, my video card got to 76 degrees as the max and my CPU temperatures to 45. Other temperatures recorded were 53, 66, and 56 as Temps 0, 1, and 2. I do not have my desktop in what I would consider an open space due to spatial limits. The front fan breathes nicely and I would argue the side fan does as well, the rear exhaust fan, however, is only six inches away from the wall. So to see these temps after playing, and considering the less than adequate position of the desktop, this fan does an outstanding job.

Exact replacement for the fan in the Flex 6400/M and 6600/M. Works fine and is very quiet.

I am updating this review, downgrading from 5 stars to 3.The type of bearing in this fan REQUIRES vertical mounting, to prevent the air bearing from failing to support the fan and prevent wear. But even if vertical, it can fail early. Out of 8 fans, one failed within seven months. These are good fans when they work, but not so good for longevity.I have a situation where a lot of fan noise was going to be objectionable, so we originally opted for a fan that moved a medium amount of air, but was very quiet. Our application uses 8 of these fans, and is near executive offices, so the noise level needs to be as low as possible. The heat load was increasing as more equipment was added, so we out-grew the cooling capacity of the original fan. I found these after analyzing the manufacturer claims for sound level vs airflow, ordering samples and doing airflow tests using an anemometer. This fan has different speed claims for the different color fans, I only tested the black. It seems that the blades deflect slightly while spinning, and the different colors of plastic have different am0unts of flex, which alters the dynamics of the blade while in operation. But regardless of the color you choose, the differences are probably small.In any event, this fan was 10 times louder than the fans it replaced, but that means it is barely audible, while the previous fan was totally silent. We can hear it some, but with 8 of them at eye level in one large cluster, the sound level is minimal, 8 is barely louder than 1. However the airflow is outstanding, and far better than much more expensive fans from more expensive brands.I think much of the secret is a very thin blade material, so thin it needs the corrugation near the wide part of the blade to reduce that flex, the other two are probably just for looks. The unit also has a new kind of bearing. It is a sleeve bearing that uses a fluid as the lubrication. This bearing was designed for hard drives originally. The bearing is probably the best feature for long life, at least it looks that way on paper. However the bearing has a downside, this bearing has just the right forces for the fan in a vertical mounting position. In a horizontal mount, the bearing does not have enough force to center the bearing if it is blowing up, so that causes the thrust surface to become fully engaged, which means something is grinding away, polluting the fluid with ground up materials, and the fan will have a short life. In theory this might not happen if the fan is blowing down, but clearly the bearing isn't designed for horizontal mounting. The fluid dynamic forces they are employing are with low precision, I'm fairly sure the hard drive version of this bearing works in all mounting positions. So this bearing can probably be improved. None the less, it could give this fan a long life if it really works as it should.All in all, this fan is the best ratio of airflow to sound level that I found. I did not test very many fans, I went for the two with the best airflow to sound ratio specifications, and compared those to my existing fans.