An A3120 that cannot be regulated. What good is that?
I think the auto translate is pretty clear. It's the decorated plate version, same as my ceramic diver has. The plate which holds the false jewel on top of the balance assembly is held by 2 stubby screws, stubby because if they were longer, they'd foul further down. For timing adjustment, the plate has to be removed which a quick QC dept won't bother to do, to get at the real adjuster.
It can be adjusted, just not rapidly like a standard movement because of the hassle of the screws. Mine was running quite fast on my wrist, but I've now got it to +3secs per day and have put the plate back on.