Top Motor Dual Bearing 40x40x20mm Fan DF124020BH

Excellent fan, one of the highest CFM outputs I've seen for a 40mm fan. It is quiet at full speed. I use this fan for a 3D printer in order to cool the plastic extruded. It does the job better than the 40mm fan it replaced. Some people say it's loud, I suppose it depends on the application. If you're looking for something whisper quiet then this probably won't do. But in my scenario since the stepper motors generate more noise on my 3D printer than this fan, the noise is negligible.

I bought this fan to add cooling to a 3-D printer I had built (Printrbot). I wanted one that moved a lot of air and that had good bearings for a long life. While I can't attest to long life, the fan does put out a considerable breeze at full speed without sounding "whiny". At lower speeds, it is near-silent. Works fine for my purposes.

I had to change it to 5v, since i have it for an aquarium and at night on the 12 volt it was too load. I have purchased others that make less noise in 12v like the Scythe Mini Kaze Ultra 40mm x 20mm Silent Mini Fan (SY124020L) but its also less air. I would get this one again since it gives you option to have 5v or 12v with lots of air power.

This fan is a perfect fit for Cisco 2950 (and I assume other) switches. Didn't work at first, but when I swapped black and red leads, it worked perfectly. Should help me with my CCNA studies.

It never worked. Return shipping costs more than the fan. I wish it worked. What else can i say. Not a quality product.

I respect the other reviewers that were positive about this item but for me it is unacceptable. Connected to 12 volts (my application and within the unit's ratings) it is very, very noisy. So much so that we're going to replace it with something else right away. Not a big deal losing $7 but it should be better.

These fans work as expected. Very easy to install. I do not see any potential issues.

This little fan replaces a failed cisco provided fan in a gigabit switch ive been using. I was going to sell it on ebay since the noise was unbearable, but i got on her on Amazon and found this fan, with some good reviews and another who had the same situation i had, he reported good results, so here i am stating the same, the fan fit into switch and works fine, hope it lasts!!!!