A sentry gun is a gun that is automatically aimed and fired at targets that are detected by sensors. The earliest functioning military sentry guns were the close-in weapon systems point-defense weapons for detecting and destroying short range incoming missiles and enemy aircraft first used exclusively on naval assets, and now also as land-based defences.
Fictional sentry guns have appeared in science fiction since the 1940s. Video games have provided a fertile ground for fictional visions of sentry guns. Fictional examples of automatic sentry guns have appeared since the 1980s, in films such as Aliens (1986).
This design is entirely fictional and is supplied with several different camouflage patterns.