Dual 40mm USB Fan with 3 Speeds Adjustable 5V PC Fan Mini Case Fan Quiet Cooling Computer Fan Compatible for PC, TV Box, Router, Xbox, Playstation

Perfect! Unit magnetically attached to the outside of my 26-port router case; you can feel the hot air exhaust at the other end of the case. This significantly lowered the operating temperature of the SFP and the router. Noise is not a problem as this is located in the basement. I will be adding a second fan to the system.

This worked very well to keep a Raspberry Pi cool. Because of were the Pi set up I cannot do a case with fan and this solved the problem. The magnets do hold but will come off with the slightest tug so be aware of that. As for noise it seems a bit to the loud side even on low but is noisy on high.

I got these to put on top of my ham radio, which gets quite hot during long winded conversations. Happily after mounting these fans; the radio has stayed relatively cool to the touch.

I bought the fan to circulate air in a small cabinet humidor for cigars (22"x20"x16", about 7040 cu. in., nominally rated for 300 cigars). I humidify the cabinet using trays of water-soaked florist foam on each shelf, but I was getting a variance of as much as 10 percentage points of relative humidity between hygrometers placed on the top and bottom shelves. I placed the fan on the middle shelf in the back of the cabinet. After a day or so, the discrepancy is 0-1 percentage points, and has remained that way for the week or so that I have been using the fan. Great! That said, I can see what other reviewers are saying when it comes to noise and minimal airflow. This isn't a fan that you would want in a quiet work environment, or if you needed to move a significant amount of air. It has a buzz about the volume of a quiet electric shaver, and the fan barely moved a Kleenex held in front of it. But, for my purposes of gently moving air in a closed environment where the light buzzing isn't a distraction, it was perfect.

Awesome for my Samsung TV box panel. Connected to the box via USB, glad that it turns on and off with my tv set.