Testing and DesignEdit
During it's testing and design phase, it was known as the "X555 Electromagnetic Launcher Advanced Technologies Testbed".
ONI Gauss Turret - A variant of the M555 Gauss Turret where the slugs produce lingering area-of-effect damage.
The Gauss turret can be found in tripod form. Like other turrets, it can be removed from its mount. Picking up the gauss turret results in a lack of mobility. The turret behaves like the M68 Asynchronous Linear-Induction Motor in previous Halo titles.