The structure is a type of Sentinel manufacturing facility, and it is able to construct an infinite amount of additional combat support in the form of Sentinels once captured by a player, which can then be added to their forces. The structure can also be captured again by an enemy player, so must be well defended. While this building does not need to be garrisoned, player's units must be near it. These structures are strongly contested due to their obvious strategic value, and so they must be well guarded by the player. The sentinel factory is only found on the multiplayer maps Repository and Glacial Ravine. The sentinel factory produces sentinels for 100 resources and tech level 1, and Super Sentinels for 250 resources and tech level 2. The sentinels are produced instantly and they must recharge before being able to produce a new unit, much like the support abilities of the UNSC.