Sunon MagLev KDE1204PKV3.MS.AF.GN 40x20mm 3pin Low-speed 5200RPM 6.3CFM

Because of the relatively slow speed (5200 RPM) this fan is very quiet(18 dBA) while still producing 6.3 CFM of airflow. Great alternative to the Noctua equivalent.

I am using this fan in a small 12 volt refrigerator, in the freezer compartment. It is quiet, and keeps the interior temperatures very even, and allows a lesser setting on the thermostat to keep sub 40f temperatures. A previous fan by Sunon that had twin ball bearings lasted 5 years in this use. It still works but got very loud. This Fan was desirable for its very low amp consumption, among the lowest of any fan available, and the reported current consumption is accurate.

The fan itself is a great product with OK airflow and low noise level. One of the two fans I received, in the sealed bag, was clearly used with visible dust on the fan blades and the mounting holes had already been threaded. These fans could be taken off used equipment and sold off as used. You can the the dirty q-tip in the pictures after wiping the fan blades with it. So overall, this was a poor shopping experience with the vendor (CoolerGuys) and it maybe a hit or miss if you get a new/low usage fan or one with heavy use and dirt on the blades.

Bought it expecting to replace my Synology's DS 411+ defective fan and it was a total let down. The fan depicted in the picture is the KDE1204PKV3 MS.AR.GN, but I received the KDE1204PKV3 MS.AF.GN, which sends an RPM signal to the board instead of a Locked Rotor signal. Apparently the item on the link ahead is the real deal, at least according to the reviews I saw, specially the one from Bradley N. https://www.amazon.com/Sunon-KDE1204PKV3-MS-AR-GN-40x20mm-3pin-Low-speed-5200RPM/dp/B007WLQAKE/ref=sr_1_fkmrnull_3?crid=3PJU0POYP7TN3&keywords=sunon+maglev+kde1204pkv3&qid=1550000910&s=gateway&sprefix=sunon+maglev%2Caps%2C271&sr=8-3-fkmrnull This was my first choice, but it would take longer to arrive and I didn't have the time to wait (I live in Brazil and the person bringing it to me was leaving the US). If you want to replace the little fan on your DS411+, keep in mind that this Sunon is 20mm thick whereas the original is only 10mm, which will require you to change the screws on it or other trickery to hold it in place. 1 star for the seller, 5 stars for the item, which is actually good, despite not being compatible. I will have to find something else to use it for.

I got a Dell 5448 switch and have had sitting around for a while. I decided to put it to use and set it up in my office. There is nothing like listening to a turbine engine all day right near your head, so I started looking. I found these and after rearranging the wires in the pin connectors they work fine and are so quiet. As far as color code for the wires Dell switch vs these. Red=Red, Black=Black, Blue=Yellow. Make sure they match the old fans and you should be fine. In my case looking at the side where you can see the pins from left to right was Red - Yellow - Black.

Oh, my gods ... SO QUIET! After a lot of research, I purchased these for my Dell PowerConnect 5324. At first I thought they were defective, and I initiated a return. After a quick break, I remembered random comments about "moving the wires", and thought it was worth a try. The existing fan wires (looking down from the top) went "RED-BLUE-BLACK". So I looked at the new fans ... they we're "YELLOW-BLACK-RED". Ahh ... so I used a sharp point, gently pressed down on the skinny slots to push out the little folded endings, and pulled the metal ends out. I pulled them open a little (else no contact is made), and then put them back in as "RED-YELLOW-BLACK". And daaaaang, I have a green LED for "fans" AND it's SO QUIET!

Great for cases when a 3-pin Noctua NF-A4x20 FLX, might not work, or just because you don't need all the "stuff" that comes with the Noctua or don't want to spend the extra money - or like black better! This is just a fan and some short wires to a standard 3pin connector - in a bag. Nothing else. Roughly the same CFM as the aforementioned Noctua, but will start at a lower voltage - handy for switches that do goofy fan speed control with voltage instead of PWM (3 pin after all).

Worked great. Much more quiet than the stock fan, but still with good cfm.