FMG-9

The Magpul FMG-9 (Folding subMachine Gun) is a prototype foldable submachine gun developed by Magpul Industries. It is a lightweight weapon built around the Glock 18 and based off the design of older submachine guns like the UC-M21 and ARES FMG, where it is able to fold up into a small box like package. This, coupled with the weapon's small size, allows it to be easily concealable. Developed as a show peice for SHOTSHOW 2008, Magpul has not announced any plans to actually produce the weapon.

Battlefield Hardline
The FMG-9 is a Submachine gun set to appear in Battlefield Hardline. Being a Submachine Gun, it will presumably be issued to the Mechanic.