

🌀 Small fan, big impact – cool your gear without the noise!
The Noctua NF-A4x20 FLX is a premium 40mm computer case fan designed for compact and professional setups like 1U servers, NAS, and network devices. It delivers up to 5000 RPM with advanced acoustic optimization for silent, efficient cooling. Included anti-vibration mounts and versatile adapters ensure easy installation and long-lasting quiet performance.








| ASIN | B072JK9GX6 |
| Are Batteries Included | No |
| Best Sellers Rank | #18,983 in Computers ( See Top 100 in Computers ) #111 in Computer Case Fans |
| Brand | Noctua |
| Customer Reviews | 4.8 4.8 out of 5 stars (2,354) |
| Date First Available | 15 September 2017 |
| Item Weight | 170 g |
| Item model number | NF-A4x20 FLX |
| Manufacturer | Noctua |
| Product Dimensions | 4 x 4 x 2 cm; 170 g |
| Voltage | 12 Volts |
W**S
Nice cooler for sff aystem
Its nice for the small pc
P**W
Silence
After replacement in switch, it became silent
W**B
High quality
Very good performance and quiet. I'm using it on 3D printer to cool E3D V6 hotend.
A**L
Super silent, buy it
A**R
I used this to replace the fan in my hub. Keeps things cool.
A**S
I have fitted these, blowing, into my Ubiquiti UniFi USG-Pro-4 and I can report the high pitch whine is now gone. Pretty handy when you don't have a rack out of the way of habitual areas! Only been installed an hour but so far so good, and I chose to use the noise suppression mounts, they aren't recommended for this application but I wanted to try it and the resonance from the metal cover is now much more subtle. Running these fans without a cover show they are actually virtually silent, but obviously, it's not recommended to run this device with the cover off (airflow etc)!
F**Z
Desde el empaquetado del producto se siente la calidad, viene con todos sus accesorios, se siente de muy buena calidad. Es silencioso y tiene buen caudal de aire. Lo usé para reemplazar el ventilador de un XVR Dahua, el ventilador original es de 2 pines, este ventilador noctua viene con sus accesorios para poder hacerlo de 3 pines a 2 pines. Los resultados fueron demasiado superiores al ventilador original, mucho más caudal de aire y sobre todo muy silencioso. Estoy muy satisfecho con la compra.
P**K
I purchased an unmanaged 5 port, 10gbe / 100gbs network switch to put in my makeshift networking closet. Closet is about 6 feet from my work station. Switch works GREAT, but has a 40mm fan that is legit 40db loud on the tech sheet for it but more like 50db in real life which is like having a conversation with a person loud. To remedy the issue, I purchased this fan. The fan itself is of the high quality and acumen for brown color tones one would expect from Noctua, so I'm not even going to touch on that. What is the most amazing about this purchase is everything else it comes with the kit and how Noctua caters to the primary use case for their customers here. My OEM fan has a 2 pin connector to the PCB. Noctua includes a converter so you can splice the OEM 2 pin together with the converter that plugs into the 3 pin coming from the fan. In addition, Noctua provides 3 tool-less (mostly) connectors for the splice. When you crush them down it squirts some kind of non conductive oil into the connections to protect it from water and dust. Made by 3M, but nevertheless a WELL thought out solution to include for their customers. Running at 4000+ rpm is extremely unnecessary for this network switch & since silence is the name of the game for me a way to reduce RPM without implementing a PWM controller in my limited space configuration. Another whammy from Noctua for this problem. Two RPM cables are included that step down the rpm without the need for a separate controller. I used the ultra low noise cable. It reduce the noise some, but the fan itself made such a difference that alone should do the trick for most people. I've purchased a lot of PC components and networking hardware over the years. Not sure I've ever felt like a company thought this much about their customer for something that costs such a small amount of money. The time and frustration they saved me is immeasurable and priceless. Good job Noctua :-)
Trustpilot
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