Noctua NF-A4x20 5V PWM, Premium Quiet Fan, 4-Pin, 5V Version (40x20mm, Brown)

Looked up the wiring diagram on Noctua to make sure I had it right, looked up an easy little PWM can script, and fired right up. Only had to plug it into 5V, Ground, and the PWM pin set in the script. Works awesome, and its the same price as the non-PWM fan. Its almost silent if youre right by it. If your more than a few feet away you wont hear it on high.

Bought to replace noisy fans in a 1U unifi router enclosure. These are noisier, though theyre also much higher CFM.

easy to install, will buy again

I am really impressed with the amount of additional cables, connectors, and mounting options provided. I ordered the fan to place inside of a fursuit (costume) head. It is very quiet, if even one person is talking you cannot hear it running. The air flow is low, but it is constant and hands free so that is very nice. I thought it might be much louder than it was which is why I ordered the PWM version. Since it is *so* quiet theres no reason to not let it spin at full speed unless your application is severely power limited.

The rubber anti-vibration pads can squeeze out and detach if you sandwich the fan between a fan guard and a Jetson Nanos heat sink then bolt it down tight.

Im using this to cool a Raspberry Pi running a 3d printing server. It would overheat causing the printer to stutter - but no longer. This fan is impressively small delivering impressive airflow and virtually silent. Im very satisfied.

Fantastic high quality fan. It is amazingly silent and includes many adapters and extras. Packaging and instructions are top notch. You really get what you pay for.

Kind of forced to use noctuas because the only other 40mm 5v 4pin fans available are tied to the Jetson nano and they straight didnt work for me so i had to get these puke colored babies which worked like a charm.

I purchased this fan as a replacement for the one which came with ICY DOCK ToughArmor HDD enclosure. I went with Noctua brand because of the reviews and I am really impressed with the product. The build quality is pretty good and noise level is perfectly suited for desktop PC installation. I was looking for a fan that can operate quietly and at the same time provide adequate airflow into the HDD enclosure. This product lives up to its great reviews and reputation. There is nothing much for me to say, I would definitely recommend it.

This is a quiet operating fan and it cools extremely well akso. It is easy to install and a Quality product!