Sentry Pylons are automated defenses of the Necrons. Despite looking like a static piece of artillery/turret, Sentry Pylons can actually move, but their style of locomotion is through teleportation as they can't fire on the move. This makes the Sentry Pylons a type of auto-piloted vehicle in a sense. Sentry Pylons are a smaller version of the Necron Pylon, these devices are used tactically either in the fields of war or to defend slumbering Tomb Worlds from outside intruders. Sentry Pylons can carry a variety of weapons of mass non-consensual Rape such as Death Rays and Heat Cannons. Some are equipped with the Gauss Exterminator to engage enemy aircraft at extremely long range. The Sentry Pylon can also be used against ground targets with no loss of effectiveness.
The first encounter of the Sentry Pylon was in the Orphean War. It was in this war that the Ordo Xenos was provided with the first confirmed and detailed reports of the "Sentry Pylon" Necron war engine, as codified by Imperial tactical logisticians. Smaller than the heavy defensive Gauss Pylon weapons previously encountered in defense of active Necron Tomb Worlds and major invasion forces, Sentry Pylons fill the role of tactical artillery support and localized air defense units. They are entirely autonomous, self-sustaining and capable of limited battlefield mobility and self-repair, making for a formidable weapon platform, while their firepower, as with many observed Necron war machines, vastly exceeds any equivalent Imperial design of similar size.
Like all things Necron, the Sentry Pylon are one tough nut to crack and sufficient firepower is needed to break apart this small engine of destruction.