NF-A4x20 5V, Premium Quiet Fan, 3-Pin, 5V Version (40x20mm, Brown)

I used the noctua fan to replace a loud fan in a network switch. The OmniJoin adapter that was included was easily usable and works well. I had to use the anti-vibration fan connectors because the previous fan screw holes were smaller than the noctua fan screw holes. The anti-vibration fan connectors were installed and trimmed, but the network switch case didn't fit properly over the anti-vibration fan connectors. It had to be shoved on, but it worked out. The fan moves a good amount of air, but not as much as the original fan. This is still enough air to keep the switch cool, while being fairly quiet. The fan is still audible (at 5v constant, non-PWM), but I believe this is mostly due to the design of the case, not the fan's fault. The box is a bit overkill and has great presentation, but I would rather the item cost less than have a fancy box. Overall, this is a great product and can make most server gear into home gear. There isn't much for competition of noctua's 40mm quiet fans, so you kind of have to deal with noctua's high prices if you need a quiet 40mm fan.

I was skeptical when the price of this fan as so much more than others, boy was I glad I still purchased it! The quality of this fan compared to others is unmatched. This fan works off of a 5V pin from a raspberry pi, which most others do not. You can barely tell the fan is on when listening to it it is so quiet. My Pi is in a 3D printed case and without the fan reaches 190C within minutes. With the fan, the pi has not exceeded 110C once over the course of months. I can not rave enough about this fan.

This fan replaced a ball bearing fan that was too loud for my application. This noctua fan fits the bill, trading off some cfm for a more enjoyable experience I have this connected to my car's usb port in the center console to cool down my phone while it's plugged in for apple carplay

A quality product at a reasonable price and is VERY quiet

Original chassis design in switch blocks flow and raises noise from turbulence. The original worn Delta wasn't much noisier when new, but chassis can be modified so this replacement Noctua is quieter. Deltas aren't typically as easy to source. Many unnecessary consumer extras

Got this for 3DFX voodoo 3 3000 and it cools it just right.

Pros: Extremely quite while moving a ton of air Reliability expected of the brand Love the accessories that come in the box Cons: If you are concerned with waste it does come in a standard size fan box so a lot of cardboard It is a great product as expected from Noctua!

This fan is much less noisy that the stock fan in the Dell Powerconnect switch that it replaced. It does move slightly less volume than the original but it is still plenty of airflow and device temp is unaffected by the swap. My only complaint is price. These are easily 30% higher than they should be. Only time will tell if they are worth the money.