Hi! I have a question on 40125S

There is a saying that 40125s can only be upgradeable if it is using ZSxx Firmware.

And for me, I can’t seem to find 40125W (I want to buy it…)
How can I know(I mean when I’m buying) that the frive is using a ZSxx firmware or a XSUx firmware?

And how can I find the 40125W ?
I mean, does the box package say that this is a 40125W or this is a 40125S ?

does the box package say that this is a 40125W or this is a 40125S ?

No, the box says nothing like that. And as far as I can guess there are only very few sellers that would tell you which drive that is .
Anyway, they ( or you ) have to install it first.
I really don’t get it why you seem to prefer the 40125W ? If you wish you can turn one into another and vice versa.
Besides, there is no major difference between those 2 when it comes to burning, upgrading and overclocking.