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

Compared to the stock Creality 4020 blower fan these were noticeably louder (15db louder when measured next to the fan). There was also a weird sound/vibration/whine on lower power (50%). Another issue I had was that these were not wired correctly out of the box. I had to flip the wires in order to get it to work with my printer which was inconvenient. I only tested one fan so it may be a dud. Overall these are inexpensive fans that’ll probably get the job done, but are louder than what they are replacing. Not sure how durable they are, only time will tell. Might be worth spending a bit more money for fewer fans that are quieter and wired correctly.