You can usually pull the existing fan and read the label...then search Amazom/Alibaba/ Etc for a match or same spec fan. They are generally not having custom made fans but instead using an available unit to keep costs down.
Cooling down a asic miner isn't a joke, if you get anyhow fan the heat will be much, it's better if OP get a high quality fan for the asic miner, fan isn't fan, grades matter here or else your asic miner will over heat every hour and reboots over and over, you don't want to mess with asic cooling Did i say its a joke? No...maybe reread what i said.
Yes i own some asics....bitmain BTC / ZEC / Sia asics.
That is why i said look at the fan label.
It gives the spec of the fan.
Look that up and get the same or a same spec fans.
There is no rocket science its fans.
It is a measure of RPM / CFM / static pressure / V/W.
I didnt say just get a fan....maybe you should work on reading comprehension.