Mark V Zeta
From Halopedia, the Halo wiki
The Mark V Zeta helmet was worn by Spartans affiliated with the ONI Xeno-Materials Exploitation Group, who were deployed on Installation 07. They found that its high-threat response and surveillance interlinks were well suited to the unique operating environment on the ring.
The following attachments are not exclusive to Mark V Zeta, and are compatible with other helmets on the Mark VII core.
List of appearances