120mm x 38mm

Okay, so, I've been using this thing for about a year and here are my thoughts. In order to use this, I bought a barrel-jack/fan connector and an adjustable fan controller that fits said barrel jack connector. Upon opening the box the first thing that you notice is the sheer girth of this unit. I mean, it feels much heavier than it should. The build quality is amazing and it runs like a top. at low speed its nearly silent and cools my mid-tower cpu case and heat-sink to a comfy 45c. I want whoever reads this to understand, I don't have a fan on my cpu heat-sink, this thing is connected to the front inside top of my case so as to suck fresh air in and blow it. It blows enough air, from that position to not only cool my heat-sink on its LOWEST setting but to also hit the fan in the back of the case. On medium, the fan sounds like what I imagine a duck hitting a airplanes turbine hears before it becomes meat shrapnel. It's just, Incredibly loud. Like, you can hear it 30+ feet away at half speed. The cooling performance though, matches the noise. I'm able to drop from 71c post Vulcan shader render to 42c in 20 seconds at half speed. Now comes the complicated part. Depending on the heatsink you use, There's little to no point in using this thing past half speed. Let me explain. The heatink can only throw so much heat, and this fan moves air so fast, after half speed, it reaches a point where it just doesn't remove any more. I am able to hold a paper towel to a wall at 3 feet from the back of my case at the fans full speed though lmao. Bottom line is, It's stupid, overkill, and I'm in love, buy three. Just don't forget the adapter and external fan controller, this may kill your power supply.

Amazing air output and noise level! I found operating it at a low 3-6 watts, it is moving as much air as most of my other 120mm fans. Crank it up to full power of 20+ watts and it's like facing a 30+ mph headwind. Thankfully I purchased a speed control to go with this. Unless you are mounting this fan inside a sound proof chamber you'll definitely need one to restrain the noise. I purchased this fan for cooling under my tractor canopy so the noise isn't that bad compared with the tractor diesel engine spinning 2500rpm. Most of the time I'm using the speed control at about 1/2 of maximum. But it's wonderful to crank it up when the outside temps are getting high. Size is correct match for 120mm mounting. The speed control I used is 4 pin version so fan connected right up. I haven't had any problems with operation. Get a speed control that permits setting a minimum speed also helps. Overall I am very, very pleased. I've bought several other Wathai fans and this one is just as well built as the others. I will definitely to buy Wathai fans.

First of all, they can be very very loud if set to the highest level of speed. This is exactly what I wanted to replace the jet flow fan cases I got originally for my pc many many years ago. You can adjust the speed using the fan control in bios or any other fan control program. I have mine set to manual because trust me if I have it set to cpu temp it sounds like it will take off...lol. Anyway, I can feel the air move and it doing much much better than any regular cpu fan. These are server fans and they can move the air. I think the manufacturers setting is off because I think it moves more than they say. Which is great for me and i have them set at 35% in the front and 45% in the back and the sound is okay. I am very very happy with my purchase. I might end up ordering one more but for now these are fine

This fan is great! It moves a massive amount of air for a 120mm form factor and at 12V no less. I'm using it as a personal desk fan, so it rarely sees full power. I will say the lower end of the fan is also quite low. Keep the control PWM however, as controlling via power is not nearly as smooth. A note on power: I saw sustained load up to ~40W which is a fair bit higher than the ~23W stated in the description. This probably doesn't matter to most, as running it all full speed is likely unnecessary, but its something to note. I highly recommend this fan, just be sure to power it with something beefy.

Moves a lot of air for its size but is noisy. Doesn’t use as much power as I expected.

These things are serious. I run them with an owltree 12v 4pin controller. Out of the box I stood them up on my desk to test them and they pushed so much air, they pushed themselves across the desk. They aren't quiet at all, but I need them to cool. Very pleased.

It's like a jet engine; both in good ways and bad. It's incredibly loud, mirroring the sounds similar to an overhead airplane taking off. Measured 74 DB on the decibel reader. CFM reading averaged about 178 with just the provided fan grill. It does put out a good amount of air, will blow papers off a desk across the room, but the noise is just overkill. Noise is about on par with my bounce house blower fan. Good price for performance if you have hearing protection though.

I built my pc with the purpose of it being a video editing/rendering system, so I stuffed in 2 GPUs, a Ryzen 7 with water cooling and 64 Gb of ram respectively. But overlooked the thermals and wondering why I was getting around 90c after a few hours. Figured out it was the front fans the AIO came with, so I swapped those puny little fans for 2 of these 5300 RPM big boy fans, and when I turn these fans up, the CPU will never go above 72c no matter how hard my computer tries. Not only do these fans push a ridiculous amount of air, they also give you a nice little audio cue to when they are working the hardest. They can also be extremely quiet when ran at lower speeds, only slightly louder than a regular case fan. Granted, they do sound like a hair dryer or a jet engine when they are at full power, but did a little noise ever hurt anyone? 100% recommend these fans to anyone who would like ice cold thermals and isn't bothered by a bit of noise.

Extrêmement puissant et donc bruyant à vitesse élevée. Très efficace

Wow.... Amazing fan!

Update: I've now had 3 of these fans fail in the same way only a few hundred hours after being put into service. They will fail to reach full speed and start making a noise. Eventually they will jam completely. After dissecting all 3 I found a failed capacitor can jammed between the rotor and the stator coils. Removing the can and reassembling (without replacing the capacitor) the fans will work at partial speed but not the full 5300 RPM. I'm reducing my rating to 1 star as these fans are NOT reliable and will fail prematurely regardless of the operating conditions. Whether it's a bad batch of capacitors or a bad design, I can't say, but a failed capacitor causing mechanical failure of the fan after only a few hours in service is unacceptable. Original review: I have a small single room ventilation system which was previously using Noctua industrial 3000 RPM fans. I bought two of these to try as upgrades, one for intake and one for exhaust in an HRV type setup. The exhaust fan seems OK after 2 weeks, but the intake (installed in a bottom to top airflow configuration taking outside air in via a filter) started making awful noises after about 48 hours and seized altogether after 3 days. I removed it and got it spinning again on its edge, reinstalled it, and within 2 hours it seized again. It’s seen air temperatures between about -2C and 10C, and would see a range from -35C to about 40C in that installed position, which the Noctua Industrial fan has handled just fine for over 2 years. So I’m rather disappointed, to say the least. I tried replacing the lubricant with some multigrade oil to see if this will help. As I said, the performance is exciting, but I can’t really stomach the prospect reliability issues in this system.

In accurate size - it’s actually 92-93mm not 120