Buy 10000mAh 7 inch Battery Operated Clip on Fan Rotatable USB Fan for Baby Stroller Outdoor Camping Tent Beach Treadmill Car Golf Cart: USB Fans - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
this one works well, 3 speed, holds a good charge & uses std usb for charging. Not sure how you’d mount. I only recommend based on the fan being dependable
Buy Schumacher 122 Turbo Fan with Heavy-Duty Clamp - 12V - for Cars, Trucks, Buses, RVs, and Boats: Fans - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
I have 3 of these...I have them clamped to my top roll bar blowing on the back of our heads and the chest of the rears. One fell once otherwise they have stayed adjusted and not flopped around going over high speed bumps.
They are very dirty and seem to be holding up so far!