M202 XP machine gun
From Halopedia, the Halo wiki
The M202 XP Machine Gun is a type of automated stationary gun turret. They were obsolete as of 2541, and used only in training the Spartan-III's. They fire stun rounds for training, and can fire bullets if needed. The gun has a minimum angle of fire, a person can stay out of the cone of fire to avoid getting shot.
They are secured to a platform by securing bolts. On the platform, the gun is hooked up by wires to: a radar array that uses radar to target, a power supply that powers the turret, and an automated fire control. They can also be disassembled and be used manually like a gun.
