4 Pack USB Brushless Cooling Fan 40mm High Performance DC 5V Speed 4200 RPM for Small Appliances Series Replacement For Desktop

I actually needed two of these and went ahead and bought the four pack just in case one of them might give me trouble. They all function perfectly and I didn't have to worry about cutting and splicing wires. just plugged them into a USB charging adapter. This was a great price for four of these fans.

im using this little fan for a desktop green house, It does wonderfully to circulate air. i wasnt sure if the moisture or humidity would be a problem but havent come across anything yet. while I have a very limited idea of what this is original for but i dont think its this lmfao. it does make a noticeable amount of noise if i dont have my headphones on its not annoying or high-pitched.

When I installed these on my 3d printer, I cut and crimped all 4 fans by normal convention (black negative, red positive). None of the 4 worked. However, I came back to Amazon and read through some reviews were talking about faulty wiring. I reversed the crimps in the JST housing and they now work perfectly! These fans have good air flow and are much quieter than the stock 4010 fan on my Voxelab Aquila (Ender 3v2 clone). Good value for the money. There's a slight high pitched whine, but it gets quickly drowned out once the parts fan, PSU, and MCU fans get going anyways. No heat creep even on long prints thus far.

Tiny, simple, gets the job done. I am using them in a DIY greenhouse cabinet. Plugged them in and they run 24/7, they are quiet idk why my video makes it sound like an airplane, just enough airflow. Literally perfect. Love them.

A great little fan for keeping your systems cool and not overheating. Just plugs into a USB port on your system, and it powers up when the system turns on (I'm using on a PS3). Slight noise from such a small thing, but it's nothing too overly annoying. Definitely a worth buy.

I use this with a mini Linux-based computer (about 4"x4"x1/2". I used a very small piece of double-sided tape to attach it to the hottest section of the computer. I did not cover any computer cooling fins. The fan immediately brought down the temperature and continued to do so all day and night. It does make some noise, but it is no big deal. And if the fan ever gives out, I have three more as backups!

Fast delivery: after 3 days of continuous operation it suddenly started a horrendous sound I could hear across the living room. I haven’t tried the other ones yet. I tested it unmounted and installed, just unusable.

I got these little fans because currently my computer tower only has a single exhaust in the back, but it has a grate on the bottom front of the case, but no real way other than negative pressure to pull the air into it. So I figured I could get these, wire them up, and set them to a switch so they could just pull the cooler air into the bottom of the case. It would circulate through and be pushed out by my exhaust fan. And while they do do that, and it does work well and helps to cool my computer tower, they are very loud. Loud enough that when I stream, I'm unable to really use them because my microphone will pick them up more so than it even picks up my air conditioner. That is only 20 feet away from me. So while they work, and they are fairly powerful for their size, they are by no means quiet.