Review on Pack Of 4 WINSINN 40Mm Blower Fans 12V With Dual Ball Bearings, Ideal For 3D Printers - 40Mmx20Mm 2PIN Connectors by James Small

Only one of the 4 was balanced enough when running for me to feel comfortable putting it on my 3D printer. The other 3 must have unbalanced blades or off-center components, as they vibrated far too much - which made them even louder. I don't feel comfortable putting any of those on my printer, for fear of print quality and vibration-induced wear on my printer.That said, I have the _least unbalanced_ fan temporarily mounted with a good duct 4cm away from the nozzle. Printing PLA at about 60mm/s it handles overhangs quite well, with _one fan_. If it were placed more optimally, and/or I had more than one balanced fan, perhaps I could handle the 60+ degree overhangs even better.I can't say I recommend my particular batch of fans. But depending on how lucky or willing you are to return/exchange, it might be worth a shot. 24v dual bearing blower fans in this size are pretty tough to find at <1wk shipping.