The Zaku Minelayer is not a new mobile suit per se, but actually just a standard MS-06F Zaku II equipped with a different style backpack.
With this new backpack, the Zaku II is adapted to play the role of a mine-laying unit. The new backpack houses several drums filled with space mines, with twelve mines packed into every drum. The backpack also has a few additional maneuvering thrusters and carries five times the amount of fuel of a standard Zaku II. However, the Zaku Minelayer requires a special loading area on a Musai to reload, launch, or land.