The MS-06FZ Zaku II Kai is a mobile suit introduced in the OVA Mobile Suit Gundam 0080: War in the Pocket.

The Zaku II was one of the second-phase production MS that have been improved by the United Maintenance Plan. The performance of the Zaku II itself has begun to deteriorate due to the appearance of Federation MS and the development of new models by its own forces, so it has been tuned up by feeding back data from new models. In addition, based on the results of the renovation of the MS-06F-2 Zaku II F2 Type, the shape and materials of the armor and the balance of the machine were more thoroughly reviewed, resulting in an appearance that is quite different from the previous Zaku II F-Type.

The most significant modification was to the cockpit, which is said to have been so good that even new recruits with insufficient training could handle it. In addition, the apogee motors in various parts of the fuselage and the thrusters in the backpack were increased and made larger, and the total thrust was increased by 70 percent compared to the previous F-Type model. On the other hand, the total amount of propellant had not changed, and the time limit at maximum combat thrust has dropped by half. The armor has also been considerably strengthened and the armament has been redesigned, so it does not lag behind the Federation's RGM-79 GM and has achieved considerable high performance. It also had the option of two different "helmet" designs. The "A-Type" helmet, which was the more common design, was similar to the typical helmet of the Zaku II series. The "B-Type" helmet, also known as "Fritz Helm" was modeled after the Stahlhelm helmet used by the German army in World War II. The Fritz helm was designed for pilots of downed machines to be able to remove the helmet dome and make repairs on their own.

Rolled out one month before the end of the war, this machine is the final production model of the Zaku in the One Year War, but the number produced was small. It was only used by some units of the Space Fleet (especially the units made up of school soldiers and new recruits), and never landed on Earth, and it participated in few actual battles.