Suzuki 2 Strokes

I just got my carb kits from Cruzinimage. Only 3 days from Japan! These definitely look to be a cut above the Keyster kits I have fooled with in the past. Especially the main jet needle. I wont be using much of the kit. Just the bowl gasket, float needle / seat and the carb top o-rings. The included main jet is marked 98.
There is something here I don't recognize. The air screw -- center bottom.. I have never seen one like that before and I can't understand why it would be included in a 74-77 kit. Anybody know what that is?

Is it possible that a different market used a slightly different air screw? It looks like a 72 screw but on a 72 the bowl gasket is a different shape.

Hi!

May be from GT250 carburetor.
see pics 26 + 27: http://suzuki-gt250.de/motornavi/motor.php?b=4

Markus