One of ZAFT's five ZGMF-X Gundam units produced in C.E. 71 using technology derived from the four captured Alliance's Gundams, the Justice Gundam was designed as an assault mobile suit. The Justice Gundam's main feature is the Fatum-00 unit on its back. This complex armament unit normally serves as the main thrusters, granting overwhelming acceleration as well as mobility when deployed horizontally and this configuration is also known as 'High-Mobility Aerial Tactics (HiMAT) Mode'. It also grants flight capabilities in the atmosphere and can be deployed as a separate unmanned unit or a subflight unit. It is armed with beam cannons and machine guns.
Other weapons of the Justice included beam sabers, beam rifle, shield, beam boomerangs and head-mounted CIWS guns. In comparison to the other ZGMF-X Gundam units, the Justice's armament is relatively simple and pales in firepower compared to its sibling, the ZGMF-X10A Freedom Gundam. However, the Justice's true value lies in its incredible mobility and the various tactics it can employ using the Fatum-00.