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)

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.

I needed some fans quick so I choose to order on Amazon rather than Aliexpress. These fans were notably quieter than some Aliexpress fans of similar specs I ordered years ago, interestingly enough I found some same spec fans like these for half the price on Aliexpress recently so I am going to try those out.

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.

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

Meh, they're okay. I needed something for my SB while I waited for a quality unit to come in. These work, I wouldn't trust them in my hotend for long periods of time. They're also a little bigger than a normal blower. I had to sand the body to get it to mount in my SB. I reused mine for stepper driver cool and they seem to working great for that.

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.

As others have noted several different brands of these fans, it was wire backwards. That was easy enough to fix but not the airflow. The 5v fans I bought on accident move more air than these. I didn't test, but they are so weak they might be 24v fans labelled incorrectly. They are quiet only because they barely move air.

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.