Review on 🌬️ Quiet Dual 120mm 5V USB Computer PC Fan with Speed Controller - Enhanced Cooling for Router, Desktop, Laptop, Receiver, DVR, Playstation & Xbox by Elton Luo

They work as expected and move a fair amount of air for 5 volts. They have grilles ready with some sort of rubber feet screwed into the four corners so they can be aligned, but a string works best. The cable is fairly short, about 2 feet to the switch and a foot to each of the fans, allowing them to be separated by about 2 feet. Nothing fancy here, you can just splice extra length if needed, or just use a USB AA extension to move them further away from the right-hand connector as a pair. They're fairly quiet, almost silent on the lowest settings, but not at all obtrusive on high settings, which is where I expect most will be using them anyway. They are designed for 0.5 A each. So if used with a really cheap 1A USB adapter, that might be all it can handle. I don't think you could build these at this price point, especially with a (probably useless) speed controller, so I'd say they represent good value. Convenient for moving a moderate amount of air at minimal cost.