2 Packs USB Fan 40mm x 10mm DC 5V Mini Cooling Brushless Box Fan for Computer Terrarium PlayStation PC Case Xbox Welding Helmet Aquarium Router

Nice big fans. These should be a good investment for protecting my new home theater equipment.

Great little fansOriginally picked these up to help get fresh air to some of my game consoles tucked into a shelf, which I still might do. Just know that the included screws are really only meant formounting to sheet metal or thin plastic, so this would take some work to mount to a wooden shelf. But a quick trip to the hardware store would take care of that. But 80mm for my use case would have been good. Fitting a 120 or 140 would have been difficult.But before I got a chance to work on that more, I got myself a 3D printer, and these fans work amazing to circulate air when drying out filament. If you search through some YouTube videos, there's a technique where you use the print bed to warm the filament to about 50 degrees C for a few to several hours to help evaporate out the water. Keeping the filament in a box creates an oven of sorts, and then adding in a fan or two to the outside of the box helps draw in fresh air and create convection. These fans work great for that.If anyone is wondering about power draw, at full speed both fans draw about 0.448 Amps at 5V. Medium speed was 0.378amps. And 0.275 amps. So really any old 1 amp charger should be more than enough to keep these going full speed without issues.Unfortunately I don't have the technical equipment to measure decibels or air flow, but they're not terribly noisy and move a good amount of air flow at the highest speed. Lowest speed is very quiet with the trade-off being much less air flow. If you're in a dead quiet room, you'll definitely notice them, so they might not be the greatest for cooling AV equipment if it's out in the open. But for a cabinet where it's mounted on the inside behind an air filter, it would probably be fine.In my use case though, I run them full blast and walk away for a few hours.Overall good bang for the buck. The controller works well. Fans move air. They do what they're supposed to.

I picked up this 2-pack of USB fans mainly to use as an aquarium chiller during those brutally hot summer days—when the tank heater’s already off but the water temp just keeps creeping up. Honestly, I wasn’t expecting a whole lot from something this small, but I was pleasantly surprised.These fans are tiny (40mm x 10mm), but don’t let the size fool you—they move a decent amount of air for what they are. I rigged them up to blow across the surface of my tank, and it actually helps bring the temp down by a few degrees, which is all I really need. They’re USB-powered, so I just run them off a basic USB wall adapter or even a power bank if I want to be flexible.Here’s what stood out to me:✅ Compact but effective – For the size, these things actually push air decently. I wasn’t expecting them to work as well as they do for aquarium cooling.✅ Super quiet – You can barely hear them running unless you’re right next to them. Perfect for setups in bedrooms or living areas.✅ USB powered = easy setup – No need to deal with extra adapters or wiring. I just plugged them into a USB outlet and they were good to go.✅ Versatile – While I use them for my fish tank, I know these could be used for a bunch of other scenarios.That said, they’re not perfect:❌ No built-in switch – You have to unplug them to turn them off unless you use a USB switch or smart plug. Would’ve been nice to have a power button.❌ Short wires – The cable isn’t super long, so if you don’t have a USB port close by, you’ll need an extension.❌ They’re not waterproof – Kind of a given, but worth pointing out if you’re planning to use them around water like I do. Just be cautious with placement.Overall, these little fans are doing exactly what I hoped for and then some. They’re not going to blast air like a full-sized fan, but for targeted cooling in small spaces—like the top of an aquarium or inside electronics—they’re great. Definitely worth having a few on hand.

The quality of the AmRunJe fan is excellent. This kit includes a 3-speed controller that connects via USB-A to the two fans. This feature provides an option to use these fans together or separately. In my case, I'm using one fan to cool my laptop and another to cool my PS4, so I'm not using the included controller. I installed one of the fans underneath my laptop holder and connected it to a USB hub that has an individual switch allowing me to turn it on and off. The fan is powerful and keeps my laptop cool. I placed the second fan just behind my PS4 and connected it to the console stand so it turns on only when the console is on. It would work great and provide even more cooling power when used together. It was easy to install. This is a great choice, considering its versatility and price.

This is a nice little 40mm fan kit. Its nice that the USB cable is split in two so both fans can run on a single cable. Its great that it has 40mm fan guards, screws and the PWM fan speed controller has three settings, and does a nice job.At max power @ 1' the db rating is 39.1 decibels (I wish in the fan world there was a set standard to measure decibel ratings, but each manufacturer keeps how they measure the noise to themselves.) My anemometer has trouble measuring small 40mm fans, but it measured 2.6M/secondThe only downsides are there's a slight parasitic draw when two fans are run on the single cable, but its hardly noticeable. Only other comment is that its a sleeve bearing.

I’m using these fans inside a closed cabinet where I keep my modem and network gear. Without airflow, it gets pretty warm in there, especially during the summer. These fans made an immediate difference. They’re small, but surprisingly effective for their size. They’re nearly silent on low and medium settings, and even on high, the noise level is minimal. The USB power is convenient, and being fully independent allows some versatility in how you place them, possibly even using a USB extension if you wanted. Overall I'm really pleased with the set.