2-Pack Quiet 40mm USB Fans with 3 Speed Control, Mini 5V DC Brushless Computer Case Fan for VR Gear Raspberry Pi Cosplay Helmet Mini PC Aquarium Roku Router Cooling Ventilation

I bought this as an extra fan to cool down my pc best thing is they have portable USB styled connection so whenever my PC is on render I add them and keep them aside once done. Highly recommended

The problem I had was that the external hard drives connected to a NAS built on a mini-pc in a homebuilt rack would run warm if a backup started while I was out of the office and the air-conditioning was off. The possible solutions were either to leave the A/C on all the time, which was stupid; or to buy some fans, which seemed like a much smarter choice.So I bought these fans and banged a few more pieces of wood onto my homebuilt rack to hold them in place. They're just wedged in there between the wooden rails on the top and bottom, pointed so the air flows toward the back, over the four external hard drives.The idea works. I had the A/C off most of the say and there were no S.M.A.R.T. warnings. The drives seem very happy now.These fans have no speed control, so they run full-bore all the time and are a bit loud as a result. I was going to wire one in, but I don't hear so well anymore anyway so I decided not to bother.The fans seem well-made. They move a lot of air. I didn't measure how much air they move, but it's enough for my purposes. The hard drives are now cooler.The finger guards should guard adult fingers okay; but I think a toddler might be able to get their fingers in there if they tried hard enough. I don't have a toddler handy to test that hypothesis, however; so I'll just advise you to not use these fans where toddlers with a love of science might want to test my theory.In summary, they're good fans. They spin around and move air, and they do it very well. Since that's all I expect of a fan, I'm giving these air-movers five stars.

Placed these on my audio amp that was getting hot and now it runs cool with the speed on low. Very quiet on low speed.

The cords are short and I needed to supply the plugs. It makes noise, but it isn't loud. I don't think I would purchase again, just because of the cord length. It works good 👍

There fans worked very good as replacement fans for a laptop cooler pad whose fan's bearings were too noisy and had to be replaced. Whereas the previous fans just had an off and on switch these fans have adjustable settings and like the other are powered by USB

I use this in my chicken coop to get some air flow. Works good. Wish it was more powerful to cool off the coop too but the air flow is very small. Just a ge the breeze