Yang Yang Shuttles

[vic]

Does anybody know what the difference is between the "b", "c" and blank letters after the model numbers (i.e. 100, 200)? There isn't a lot of information out there. The wierd thing is that they have "practice, tournament, special" grades for all models.

[Kelvin]

Hmm... I believe this applies to all shuttles.
I'm not sure about Yang Yang, but perhaps it could be the feather quality, or grade itself?
Either that or, it has to do with the altitude that the feathers are angled at, and which sort of weather they're best suited for???
I don't quite know about Yang Yang... I'll ask for you.