It is one of the three Silver Hawks available for Force's unnamed main character, the other two being model FFSA-0019 and model FRSA-6351. ZZ9X-0001 is Green to distinguish it from these two other models (being red and blue respectively). It was originally used during Darius, making it possible that ZZ9X-0001 is a new name for model 3F-1B.
Taken from select screen
Silver Hawk Type-1 DEV-NO ZZ9X-0001
- Roll Out- PLN "Darius" Exodus War