Review on O2COOL 5-inch Portable USB or Electric Fan in Black and Gray by Tristan Graham

Great little USB car fan. I bought two and attached them to the 3rd row window with clear 3M double sided tape. Both fans were connected to a RAVPower 2680 battery pack and only used 50% for a week of travel with a minimum run time of 7-8 hours per day. The noise level isn't too bad, but it vibrates a lot. The power button is loose and the USB power cable is very thin.