Difference between WDBHG70000NBK-02 and -01

What is the difference between WDBHG70000NBK-01 and a
WDBHG70000NBK-02 ?
I own a -02 and have an opportunity to pick up a -01
Thanks

The 01/02 issue could simply mean if it is the first or second production run of the given model number.

Often the Product Overview sheet can give some clues; it does, but only as far as the different model numbers made for different countries. I had to do a Google search for it, because it has been pulled from the WD site, but is still on their server somewhere. Here is the link, so see if you can gain some insight from the last page showing different model numbers.

Thanks. I will take a look