Misriah Armory

From Halopedia, the Halo wiki

A Misriah Armory facility on Mars. From Halo: Arms Race.
Misriah Armory
An under-construction Marathon-class heavy cruiser at Misriah Armory on Mars, as depicted in Halo: Arms Race.
Another Part of Misriah Armory
An M6G2 magnum stamped with the Misriah Armory text as depicted in Halo: Arms Race.
MISRIAH ARMORY Enscribed on the side of a M6G Magnum

Misriah Armory is an armory which produces many of the objects used by the UNSC. It is also where the trailer Halo: Arms Race is set, as you can see the name enscribed on the side of a pistol when they come down on a shelf.