Returning from the original Aperture Science, the Type 2 is an updated and upgraded version of the original Sentry Turret. The Type 2 is accompanied by two earlier scrapped models refitted for work on Site-30.

Type 2 Idle SentryEdit

The main defencive unit. Its primary purpose is to be deployed in key areas around the site, mainly the Killing Corridor before the entrance to the inner site. Turrets are also deployed during Containment Breaches.

GLaDOS can 'spawn' turrets in any location she is present at so long as there is adiquit space and energy for initial teleportation.

Type 3 Mobile SentryEdit

Small spherical unit designed for mobile deffencive and offensive objectives. GLaDOS employs these units for off-site recon and offense.

Type 4 Heavy SentryEdit

An oval-shaped unit designed to use 12g shells instead of 9m rounds. The unit is designed for larger SCPs such as 682.

Only one is currently built with more qued for production. The current unit it nicknamed 'Boris' for its bulky design. 'Boris' accompanies a squad of 15 Type 3s as GLaDOS' personal 'kill squad.'