Vktech 5Pcs Black Brushless DC Cooling Blower Fan 5015S 5V 0.1-0.3A 50x15mm

If you're planning on using these for a 3d printer part cooler note that out of the box these will only run at 100% fan speed and will make a whine at any other speed. These are not PWM controlled so you'll need to add a capacitor in parallel to smooth out the PWM signal to direct voltage, I slapped a 50V 100uF capacitor I had lying around in parallel with it and it works fine for my 3d printer now.

Made air fillers with these and gave to friends too. At 1oz, you can't beat the size and convenience of filling your sleeping pad with your phone charger while you set up other stuff. My favorite camp add this year. I found a youtube on how to make them. Google DIY air mattress inflator. All of the fans worked fine, but if you remove the solder from the pre existing wires on these, you can't get new solder to stick on them at all to reassemble. I learned on my first one and just used the existing wires on the other 4.

The media could not be loaded.  When these things work they are really quite good ... very quiet and a good amount of air flow. However, the first package of 5 I received had 2 that worked perfectly, 2 that turned very slowly with almost no air flow and 1 that was completely dead or at the very least the fan blades were stuck and could not even be turned manually.I really hate it when something cheap shows up DOA even worse is when a few are fine and the others are dead but I contacted Amazon and they made it all good quickly sending me a working set.I gave these 3 stars because even though they feel like they are well made and I now have 5 that work I just have to wonder about the quality. For $2 each they are a good deal and if all 5 worked the first time I would have given them 5 stars.I suspect those reviewers who stated these fans are slow or put out minimal amounts of air received bad sets, when these fans work they put out a good amount of air.VIDEO: This is just a quick cellphone video to show the difference between a properly working fan and one which is "slow" and has very little air flow. Both fans are wired together and then to the same power source. There is a piece of post-it paper on each to help visualize the speed. The slow fan needs a boost to get started and cannot even move the piece of foil while the good fan blows it quite easily. The sniffling sound is actually the good fan blowing the piece of foil off screen ... sorry ... I let the video run a few seconds longer so people could hear the sound of the fans. It's actually a bit louder in the video, there is a slight hum normally but barely noticeable when in a project box.

These are excellent! I have two (parallell wired) inside my Kylo Ren helmet and I never have to take it off. Just had to change the connector so I could use my spare lightsaber battery. My max is 10 hours straight, no overheating or any issues. I’ll be putting these into all my others. It should also be noted that the Ren helmet is notoriously cramped, these don’t touch me all with their low profile.

The media could not be loaded.  I was skeptical that all 5 blowers would function after reading other reviews. I tested each one out of the bag and was pleased to find 5/5 functioning as advertised. These are decent quality and pretty quiet. Would recommend if you are looking for a small 5V DC cooling blower.

Blow a lot of air for their size.Have others in this style and size, but they draw far less current. These draw 0.3 A. Others draw only 0.02A. Yes, these blow more air, but not 10X more air? Using them on battery, so current draw is important. Nevertheless, I like these fans.

Most of these fans quickly develop this issue where they spin up fine for a minute then start making this horrible grinding noise because they're misbalanced or the bearings are bad. The RPM drops enormously when they're making this noise and they don't maintain temperature nearly as well. But they are cheap and come in a pack of bunches, so probably one or two will be good. Just don't buy it if you need this exact number of fans, some will certainly go bad very quickly. I can't complain too much because hey, if you cheap out like I always do this is going to happen sometimes. You can only cut so many corners. I'm coping with it.

I use these to cool the tower on my kegerator. I doubt they were intended to run 24/7 so I'm generally pleased that the one I had before these lasted almost 2 years. I bought the 5 pack because it was really inexpensive and hopefully they will each last a couple of years and I won't have to buy any more for ten years.