Gemeinhardt 22SP, 2SP, 2ESP

I am usually pretty good at knowing my flute models, but this has gotten me baffled. I know that they are all student model closed hole silver plated flutes, but what is the difference between them?

A new student of mine came in the other day with a 22SP so that is what had gotten me to wonder.

The 22SP looks to be the same as the 2SP. Probably a dealer/web difference. The newer scale Gemeinhardts are 70 series. Check the headjoint. The 2SP normally comes with a model J, is it still a J?