I have 2 S for Air Flow in front, a Diamond Fan that will hardly have any opponent, let alone with the price that is now below 30 euros. The motor is really quiet, even at 400 rotations per minute, you can't hear the motor.
It's not suitable for cooling! There, you should go for the F series or the new A.

Only 1 was purchased as a test and placed in the front top slot of a CoolerMaster Masterbox NR600 (a case in which the addition of another fan is recommended by the company itself).

The temperature on the MSI GeForce GTX 1650 4GB Gaming X GPU dropped from 35-36 °C to 32-33 °C, while on the Ryzen3600 processor, the temperature ranges lower at 37-48 °C. The measurements were taken in idle mode and at a room temperature of 20 °C.

In addition to the fan and the extension cable it comes with, the package also includes 24 rubber pads (4 pairs in 6 different colors).

The reason I chose it was because in its category, it combines high airflow, low noise (dB), and a significantly higher quality and smoother noise profile compared to other major companies (based on the recordings I heard).

It is truly SILENT. I have 3 of them in an NZXT h510 case. You can't hear their mechanism like in the previous ones (2 x Cooler Master Silencio FP 120 PWM), you can't hear the airflow like an electric vacuum cleaner (2 x NZXT 120mm case fans), you can't hear anything. They make you wonder if they are actually working! Finally, I have a silent PC on my desk.

Amazing fan quality. I regret not investing in Noctua earlier.

Note: If you are interested in Noctua fans, it might be useful to see which ones suit your needs through their website:
https://noctua.at/en/which_fan_is_right_for_me

I wasted 1.6dB more noise to see a difference in temperatures inside the case.
I am amazed by the performance of these fans. I have been fooling myself with other "silent" fans for so long. I use them for front intake in a Corsair 780t case. Connected to the tower's controller for 3 different speeds. I would describe the 1st speed as "Quiet", the 2nd as "Normal", and the 3rd as "Airflow". The PC always starts with the Noctua fans at max speed. In idle conditions, web browsing, watching series/movies, and listening to the radio, I stay at speed 1. When working on graphic programs or performing more than 2 tasks simultaneously, I switch to speed 2. For games (not many), I go to speed 3.

Extremely satisfied with the change.

...The PWM cable is very helpful for hiding all the cables behind the motherboard.

Yes, I recommend it. Yes, I would buy it again.

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Excellent fan. Completely silent, with a very good airflow price. What else can one ask for from a fan?