Combat sentry prototype MkIV

 is a robot in Fallout 4.

Background
This prototype sentry bot was developed shortly before the Great War as part of a top secret research effort by the United States Air Force and an unknown third party. It was unceremoniously dumped at the robotics disposal ground by men in black, together with its activation and control holotape. There it sat, until 2287, when the Sole Survivor could choose to activate and utilize it. Such as sending it to guard one of four locations: USAF satellite station Olivia, south Boston military checkpoint, Revere satellite array, or Fort Hagen.

Characteristics
One of the most powerful robots in the game, the sentry can be self-destructed or used to clear higher level areas, like the Revere satellite array.

Locations
Robotics disposal ground: amongst the vehicle hulks.