Lost in tech

BOUGHT 2 WD40EFAX FROM NEWEGG SUPPOSED TO BE 4TB 256 CACHE, WHEN i TRY TO FIND OUT IF i GOT STIFFED ? i TRIED WDC AND ALL HAS THE NEW FULL RED COVER but mine is the old white red label no cache marked on it . How do I find out if it is 256 cache?

It is see Page 3 HERE

thanks I saw that my question centered around the old label instead of the new full red label,
they seem to work okay was just curious why the didn’t have the cache marked on the drive like all my other ones are, maybe returned and relabeled??