In order to enter this room, the player needs to acquire the USB Dongle Key and place it at the PC located in the S.T.A.R.S. Office.
The Armory contains the Lightning Hawk for Leon and the MQ 11 for Claire, the Letter to S.T.A.R.S. Members is also present in this room which is required for the Bookworm record and the Lore Explorer award.
Because the S.T.A.R.S. Office itself is a safe area, no enemies can be found in the Armory as well, including the Tyrant.