It's not your biggest fan, but it's a big fan for your phone!

EDIT 8-13-17: Pieces now snap together. No bolts, no soldering, no glue. The width of the phone-grip is now adjustable so it should fit most phones.

After moving back to Florida I got tired of my phone overheating so I went to discuss the problem with my Fan Club and I happened upon several 40mm x 10mm 12V fans hanging around the Club and waiting to sub-in for my printer's cooling fan. But now, with one of those fans, a few quick prints and a 9V battery my phone is cooler than ever!

This thing is designed to fit snug on this phone case for a Galaxy S5 but it's pretty adaptable. I recommend PETG for this.