Got a small package from china, too.
As I've murdered by my own imbecility my neat and handy AD587 reference board (note to myself: they don't like reverse polarity supply at all
), I found and ordered some quite cheap AD587 (missed the opportunity to get one of the boards DC1MC discovered).
They arrived in good shape, looked new and pristine, but were quite obvious fakes. Unadjusted output looks OK, but temperature drift and power supply rejection is way off. Also, the external adjustment range doesn't meet the datasheet at all.
At least I've got the refund within half a day and no discussions.
The other item is that neat isolation amplifier (ISO122), quite cheap too.
These also look unused and shiny, and are working too. There's not much of a choice of chips one could package as a faked ISO122 that is working and behaving like an ISO122, so I believe these might be the correct chips inside. But they're at the margins (and somewhat over) of their specs (fuil scale gain, linearity), so I think these might be factory rejects that found their way to chinese sellers.