The prisms below are a sample of what the prisms for
each of the sets in the PP series look like.
As you can see, they have changed throughout the series,
finally ending with the GT sets.
The styles will stay rather consistent for the sets
they are marked for. So if it says set 9 to 11
then the prisms for those three sets will have the
same template or style. Sets 4 and 5 have the black boxes on the
side and the bottom, set six doesn't. Some don't change much from
the previous one. Others change considerably. Set 21 is kind
of out there on its own.
It is the only one with that style.