Noctua NF-A4x20 FLX Computer Case Fan - Cooling Components (Computer Case, Fan, 4 cm, 3700 RPM, 5000 RPM, 4400 RPM)

This thing is so quiet compared to the stock fan on many of my switches. The kit includes everything you need to mount it including an interface that lets you cut the wires from other switches that have unique connection. Great value for the money. It fit in my TP Link switch no problem and halved the Db rating.Noctua has a reputation for quality fans that is well deserved. Make sure to buy one that matches the voltage requirements of your product. Some use 12v headers, some use 5v. A 12v will not work on a 5v header.

While not as quiet as other Noctua fans (obviously, given it's size and RPM), it's a huge improvement over other similarly specced server fans. It moves a good amount of air while maintaining a sound profile that lacks any of the whining or high-pitched hums that other 40mm fans tend to have. If you're concerned about sound and/or build quality, this is a solid pick.

used this to replace the fan on a IC-2730...SO MUCH quieter! hardly notice when the fan turns on whereas the original sounded like a jet engine. Highly recommend for this use and anything that needs a quiet fan.

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:-)

I replaced the fan on my Icom ID-4100 with this and wow, what a difference. The original fan literally sounded like a jet engine and was extremely annoying. Finally replaced it with this fan and the difference is night and day. I literally can barely hear this fan when it is on high yet it seems to move plenty of air. Definitely recommend this one if you need quiet airflow on electronic equipment.

Great little fan. Good value, nice cable length. Not the best look, but if you need the airflow, this is the way to do it efficiently and without a cumbersome 120/140mm fan. It's actually more effective at cooling your HBA cards by being placed directly over the heatsink fins.

Used as a replacement for the old and loud Delta EFB0412MD-R00 3-Pin fan that started to make rattling noise intermittently on my Cisco SG200-26P PoE Switch. I'm guessing the bearings on it were the cause and it gave me a reason to look for a replacement. After doing some research online and for my home use application, settled on this Noctua NF-A4x20 FLX fan and it worked after some modding and is noticeably quieter.I've read people using the comparable Noctua PWM fan as a replacement but that's a 4 pin fan as opposed to this 3 pin fan. Looking at the Noctua fan schematics, the additional wires on their fans are for the RPM speed signal as well as the PWM signal. These additional wires should NOT be connected to the Cisco switch as the third blue wire found on the Delta fan as well as the fan header is meant for the Locked Rotor Sensor wire that these Noctua fans don't have (wish they sold one so you didn't have to mod these).Be aware that the pin layout on the fan header of the Cisco motherboard is different than the pinout of the fan so it's not as simple as just plugging it in. I used the included adapter cable with the loose black and red wires along with the OmniJoin adaptors. I snipped the wires from the original Delta fan, connected the black (-) and red (+) wires and it was good to go. A word of caution here with the blue wire as if that's not connected, the switch will think the fan is dead and will throw a fan error. To simply get rid of this error, I just stripped the blue wire and connected it to a nearby ground screw. If you do this, there's no way of it knowing if the fan dies but it's not a big deal for my use.Worked for me after some modding and is quieter. Even if it doesn't push as much air as the original fan, the lower noise is a good compromise for my application. Using this switch to power my PoE cameras and so far so good.