- "Fight for survival around mysterious Forerunner structures on Installation 04."
- — Halo Waypoint - Halo Bulletin 11/9/11
Installation 04 is a Firefight map for Halo: Combat Evolved Anniversary. It is the only Firefight map to feature Marines and ODSTs. There are always 4 ODSTs at the beginning of each game all of which stay around the area of the main structure in the center. They slowly descend to ground level as the waves progress. In addition to weapon drops at the end of each round, Pelicans may sometimes drop Warthog with ODSTs to aid the SPARTAN players, and to make things difficult for the Elite players.
- This is the first ever Firefight map to have Human AI allies.
- The map hosts an easter egg in the far building from the first spawn where a Monitor will appear behind the glass door at the beginning of a game. When approached, the text "Change weapon with ally" will pop up, showing a Focus rifle but no swap can be made.
- The map has similarities to the Quarry area in Forge World. Other resemblances are the massive rock spire with trees in the background and a cliff to the left that has several trees on it. Also notice the vast ocean, like in the map.
- The spinning windmill generates plasma and opens to cool.
- Each ODST always has a specific loadout. The first has an Assault Rifle/Shotgun loadout, the second has a DMR/Magnum loadout, the third has an Assault Rifle/Magnum loadout, and the fourth has another DMR/Magnum loadout.
- Each ODST dropped from a Pelican will carry an Assault Rifle/Magnum loadout.
- Each dead ODST drops both weapons on death.
- Right before every bonus round every ODST on the map is forced to die.
- The first four ODSTs stick to the middle structure and never stray to far from it. ODSTs dropped from a Pelican however have a "follow the player" scrip and will always be within meters of a player anywhere on a map.
- Only ODSTs dropped off via Pelican can enter vehicles (Warthog, Mongoose). The four ODSTs that spawn in the beginning on the structure will not ride with the player.
- There is a GRD Doll on this level, just like the other 6 maps from the Anniversary map pack.
- This is the only level where the player can kill Human AI as an Elite.