Halo: Fleet Battles – UNSC MAC Platform Upgrade

From the publisher:

Magnetic Accelerator Cannons of unsurpassed lethality were used to defend the planet of Reach. These devastating orbital defence platforms will add a new element to the game of Halo: Fleet Battles in the form of fixed fortifications that form defensive lynchpins behind which players can rally their fleet. A cool feature of these models is that it can be mounted both horizontally and vertically.