Question about the Babolat Aero Storm

I have 3 Babolat Aero Storms (the red one) and I just realized that one is a different weight than the other three. They all have exactly the same paint job and I had thought they were the same racket. However, 2 of them are 320g and the other is 300g.

I looked online for a review, and the specs listed were 343g. Anyone know what's going on?
Unstrung - lighter vs strung - higher. Racquetfinder uses average mass of 3-5? frames. Look at TWU for frame customizing tips or in the Racquets forum. Babolat's QC is notoriously bad unless you were lucky.
There was a heavier and a lighter version pre-GT. The GT rackets have tour written on the heavier frames, but I think the specs printed on the racquet are the only way to differentiate the pre-GT weights.