5015 Brushless Cooling Fan 4PCS 3D Printer Blower DC 12V Fans 50x50x15mm Fan for Hotend Extruder Heat Sinks with 2 Pin Terminal and Other Small Appliances Series Repair Replacement(12V 0.18A)

I mounted two of them under a Ham radio to keep it cool when transmitting.

Simple, solid color, quiet operation, powerful airflow. Helped me so much with an overheating moto monster control board. Just placing this on the top of the chip was enough to prevent thermal protection from kicking on.

I bought this to replace the fan in one of our https://www.amazon.com/gp/product/B07VGLVSQG/ GENIANI Ultrasonic humidifier's. It was a perfect fit, but I had to reverse the positive and negative pins on the connector, which was easy enough.The new fan seems to run at a higher RPM than the original one, so the jury's out on how that will impact the humidity in my house this winter.

The blower is well suited for cooling the print from a 3D printer. After printing the mounting bracket and duct work the combination works well for cooling the extruded part and a little too well on the build plate. Some insulation was needed on the build plate to reduce heat loss from the underside and compensate for the additional heat loss from the forced air from above. The blower works well and is extremely efficient.

Two of four fans were with cut wires. And there is printed message for me inside of package"Wires cut of 2 fans before shipping to me"

Bought these for an Ender 3 part cooling fan replacement. First of all, the wires are only about 12" long, which is way too short to be a direct replacement. To be fair it does show the wire length in the product pictures, which I saw only after I started this review. However it does say "for 3D Printer" in the description, so one could hope it would fit properly. The other issue is that the wiring is backwards. Since I had to splice in extra wire anyway due to the short length, I took the standard wiring scheme of red + and black - and wired it appropriately, however the fan did not work. After some troubleshooting, it turns out the red wire is soldered to the - terminal on the fan and the black to the +. After fixing it, it does spin and is pretty quiet. So....if this fan is the only one available, save the wiring from the old fan and plan on splicing it backwards.

Fine, quiet enough high throughput fan for little money.In case you buy a 12 v instead of a 24v as I did for my ender 3 pro, you can stick a 130 ohm resistor in series with the fan to make them work, you will immediately smoke the motor otherwise.Also on the ender 3 the mounting holes don't line up, but the surface is easily gluable so no problem there.

This fan moves so much air, I had to reduce it to 50% power because it was making my hotend so cool that my firmware thought I had a thermal runaway. It is very quiet at 50%, at full tilt, it sounds like an airplane taking off. A very powerful fan and it's nice to have some backups.