I picked a couple of those small fans from WALMART just a few weeks ago and they were the USB types and came with a 120VAC to USB adapter. Just so happens my truck has those USB connectors on the dash...
Already had one of those fans blowing on me while waiting for moma bear to get done shopping at Walmart... Pretty neat I thought...
When camping and sitting around the patio area under the awning we always have a 20-inch box fan running...
Moving air works great except when camping near the beach in South Carolina. I never saw so many little bitty mosquitoes... Even the wind coming in from the Ocean didn't keep them under control.
They were so small I don't think the screens in the window even slowed them down...
This was some private property camping on Johns Island at Charleston...
Roy Ken