Because of its versatility and adaptability as an all-purpose mobile suit, the tried-and-tested MS-06 Zaku II had seen numerous variants developed for various roles, one of these being the long-range Zaku II Propellant Unit. The MS-06 Zaku II, which was already recognized as Principality of Zeon's main mobile suit, was used as an experimental platform to extend its cruising range and operating time through the installation of prototype propellant tanks. These propellant tanks were a plug-in type meant to be fitted on special latches located in the front and back of the unit's torso, and a total of six were added onto this trial machine. With these modifications, the Zaku II Propellant Unit was able to operate for about 5 times longer a distance than a regular Zaku II. Despite these enhancements, the addition of the propellant tanks caused serious difficulties with the Zaku II's structural integrity, and no changes were made to the base frame to alleviate this problem. The Zaku II Propellant Unit's movement and mobility were hampered by the tanks, and the carrying-out of complex movements through AMBAC systems became impossible for the pilot.
During its high-speed test run in space, the MS-06 Zaku II Propellant Unit managed to achieve a range 500% farther than a regular Zaku II. However, towards the end of the run, extreme vibration caused ruptures in the propellant tanks and caused them to explode, destroying the mobile suit and killing the pilot.