2 Packs 5010 50mm Fan -50mmx50mmx10mm Dual Ball Bearing Computer Fan 3D Printer Fan Thermal Fan,12v DC 2pin UL Certified Long Life Cooling Fan(Speed:4000RPM)

Good air flow with very little noise. While these 4000rpm fans aren't silent, they don't generate much noise either. I'd put them at a level equal to whispering. I use them in a modified li-ion/NiMH intelligent charger and it does a great job keeping it cool. I've also used Noctua 40mm x 10mm fans which are extremely quiet, but the Noctua's don't move near as much air as these do, so less cooling. These have been holding up very well, so I purchased another set.

I installed one of these in my Dynamite Prophet Quad Lipo battery charger. I hah worn out the original fan bearings. The only issue was a plug difference. I had to replacs the plug on this fan with the plug on the original and lengthen the wires by a couple inches. Works great and moves a lot of air. The second fan is a spare. Saved me about $200 by not having to replace the charger. Relatively simple repair.

They're a bit louder than I was expecting, but slightly quieter than the fans they replaced and move a bit more air. I ultimately decided to get a 40mm fan from a manufacturer known for their quiet, high power fans, with a 3d printed 40->50mm adapter. Having said that, these aren't bad fans.

Mounted great and works better then the old original

Should be in inches

Great fans!!I can’t tell you about the longevity I just got them & installed them and they push a lot of air!!I don’t feel they are to loud, They sound like a fan to me.

Anyone who has replaced standard automotive bulbs with LEDs in a CANbus system knows that you need to install resistors to avoid a failure indication. These resistors get extremely hot and you must be careful where you mount them. To deal with this on my BMW motorcycle, I mounted the resistors on a heat sink in a protected, yet open area (under body panels on R1200RT). I mounted two of these fans to help dissipate the heat, and I love them! They are high quality and easy to install. Obviously noise is not a factor for my installation, but just trying them out, they are quiet and could be used almost anywhere.

Used in cooling P.I.D. control cabinet. Work great.