The Fiber Optic Probe is a tool of stealth used by UNSC military personnel. Fiber Optic Probes are small, wire-shaped devices equipped with cameras on one end, and an input that is plugged into an outlet on a helmet on the other end, so that the wearer can see through the camera via their HUD.
Fiber Optic Probes allow the wearer to see around corners or through small spaces without having to reveal their positions by looking up and exposing themselves to enemy fire. Some of these probes measure at least three meters long.
It is unknown if regular UNSC forces, such as Marines, can utilize fiber optic probes like ODSTs and Spartans can due to the lack of a dedicated HUD system. However, the CH252 Helmet is equipped with HUD abilities, which leads to the fact that use of the Fiber Optic Probe would very well be compatible with standard UNSC Marine forces.