Forerunner automated turret

The Automated Turret is a form of equipment similar to an immobile Sentinel that acts as an automatic defense system(deployable antipersonnel turret) for the player and first featured in Halo 3. It is so far only encountered on the Halo 3 levels The Ark, The Covenant, and Halo. It is not found on any multiplayer maps. The auto-turret is dropped in an area where you want to defend. Once deployed, it will automatically shoot at the enemy.

Function
This small robotic turret is Forerunner technology found on the Ark and resembles a stripped down Sentinel. It fires a thin, blue beam at enemies. This device is extremely adept at targeting and destroying Flood of all kinds, although it can be used to kill Covenant forces as well. It is extremely powerful and will kill a fully-armored Brute in two shots. Technically it can be considered as a type of Sentinel.

Its HUD symbol is a silhouette of the contraption itself and vaguely resembles the symbol for the Power Drain.

Disadvantages
Due to programming issues, the turret has major problems picking out targets and more often follows allies with its targeting system.

Also, upon the betrayal of 343 Guilty Spark in the level Halo, all Sentinels, including the Automated Turret, will fire upon you.

Trivia

 * This piece of equipment is unavailable in custom games, matchmaking or Forge.
 * If these turrets are deployed before the destruction of 343 Guilty Spark in the level Halo and survive, they will attack you, taking out the player's shields on Normal difficulty or killing the player in one shot on Heroic and Legendary.
 * On The Covenant, during the part where the Flood ally with you, the turret will shoot at the Flood and vice-versa.
 * The Auto-Turret can help you score campaign meta-points, although this sort of information is unknown.
 * The Auto-Turret has an odd tendency to "bounce" when a player runs into it, and even more interesting, when it lands it seems as if it just falls on an invisible platform, rather than float loosely back into position.