I got some Comair Rotron fans, that fit the spindle motors on some of
my CNC machines..
They lasted about a week, before the plastic fins/body split/cracked,
and they failed. Noisily.
I thought the first set was a fluke, so I changed to another, and sure
enough, the next set failed too.
I just got off the phone with a friend who services Radio, and TV
transmitters, and he was complaining about replacing Comair Rotron
fans in the transmitters, except when they fail it takes out several K
$ worth of tranmitter modules. Again, he was seeing about week of life
expectancy.
These fans were all Hecho en Mexico.

Any ideas about high quality, Reliable muffin fans? Brands to avoid,
or to prefer?
Are all the others made in China, from recycled trash bags now days?

These IIRC are the 6-7" fans.