Hardened External Sensor Array-External
From Halopedia, the Halo wiki
The Hardened External Sensor Array-External or "HESA-E" is a MJOLNIR-compatible device that is attached to the helmet. This equipment is standard-issue in Beta-5 Division security units. The cost of one HESA-E unit is 20,000 credits.[1]
Trivia
The HESA-E was present in the Halo: Reach Multiplayer Beta, but was renamed in the final game to the Hardened uplink/remote sensor package.
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