SECURITY-class Mjolnir

SECURITY-class Mjolnir, also designated as the MJOLNIR Powered Assault Armor/M variant, is a MJOLNIR armor variant adapted from an infiltration prevention suit designed by Misriah Armory.

Development history
The Security variant was first manufactured in the Misriah Armory facility on Mars in 2528. After Mark V was released, this armor was adapted to its use. Like most MJOLNIR variants, the later model of the Security helmet had been upgraded to be compatible with all MJOLNIR Mark VI variants. The Mark V iteration of the helmet is compatible with CBRN, UA, CNM and HUL attachments.

After the first wave of GEN2 systems, based on requests of veteran Spartan-II and Spartan-III operatives, the UNSC Ordnance Commission considered reassessing a refined and upgraded version of the EVA-class Mjolnir suit. This led to the creation of the WRATH-class Mjolnir where its right shoulder pad is based off the Mark V Security shoulders. SECURITY [GEN1] helmets continued to be used by Misriah Armory's executive protection teams after the Covenant War. These helmets have been upgraded to be compatible with GEN2 systems, though corporate representatives balk at releasing its custom VISR. As late as 2560, GEN1 Security shoulders could still be requisitioned by Spartans, upgraded to be roughly equivalent to GEN3.

Design details
The GEN2 variants helmet has two watchdog AIs hovering at the edges of the SECURITY VISR interface, alert for cyberintrusion attempts and sensor anomalies that could indicate subversion of connected surveillance networks. The armor also seamlessly integrates with Navy networks and security constructs.

Development history
The GEN2-era Security set was built to Spartan branch requirements for ship and station defense personnel.

Design details
The GEN3 Security helmet is specialized in cyber-defense, with dedicated watchdog AI hosting hardware to locate compromised battlenet branches and burn out intruding constructs.

Halo 3 - Mark VI
The Security armor is available as an armor permutation in Halo 3. The set consists of a helmet and shoulders; in the Xbox 360 editions of Halo 3 the helmet additonally comes with a small antenna attachment for the right shoulder. This was retained in the launch-era version of Halo: The Master Chief Collection, though the addition of Halo 3 on PC and the start of Series 2 saw the antenna detached from the helmet and selectable as its own chest option separate from the Security helmet. Later on in Series 7: Elite, the antenna chest option was removed and reverted back to only displaying while the accompanying helmet was equipped. If any of the chest items from Halo Online or Halo: Fireteam Raven are equipped, the antenna simply does not display.

The helmet's most noticeable feature is the larger, more prominent "figure-eight" shaped visor which looks almost bug-eyed. It bears resemblance to that of a modern day fighter jet pilot helmet. This helmet is inspired by the protagonist of Marathon, although the mouth is covered. The helmet is large with a small raised section on the forehead in the form of the Marathon logo. Wearing the helmet will also add a small antenna and dial to the right shoulder.

Halo: Reach - Mark V
"The MJOLNIR(M) variant helmet was manufactured at the Misriah Armories facility on Mars in 2528."

The Security armor returns as an armor permutation in Halo: Reach, mostly unchanged from the Halo 3 incarnation - though with the removal of the antenna chest. The Security right shoulder is equipped with a Kukri knife, and is used by Emile in the campaign. Halo: Reach introduces some additional similarly-named armor, the UA/Base Security set - details on the Base Security addons can be found here.

Halo 5: Guardians - Upgraded GEN1 and GEN2
Security returns as an armor permutation in Halo 5: Guardians, after a noticeable absence in Halo 4. The armor has been redesigned for GEN2, though retains some characteristis of the original Halo 3 and Reach iterations. A Reach-styled iteration was later introduced in the Memories of Reach update as the Security [GEN1] helmet, with the right shoulder also appearing on the WRATH armor set based on that worn by Emile.

Halo Infinite - Upgraded GEN1 and GEN3
The Security Mark V shoulder pauldrons return in Halo Infinite, available under the SAP category for the Mark V(B) core. A Halo 3-based interation of the Security helmet, alongside an exclusive helmet attachment, was introduced as part of the Aquahex Super Bundle at the start of Season 03: Echoes Within.

Trivia

 * The SECURITY-class helmet (as well as the Mark VI version's pauldrons) is based on that worn by the protagonist of the Marathon series, who is known only as the "Security Officer". The Marathon logo is featured prominently on the Mark VI version of the helmet (just above the visor) in Halo 3. The Mark V Security helmet in Halo: Reach and Halo 5: Guardians lacks the symbol, likely due to intellectual property concerns (as Bungie retained the Marathon IP after leaving Microsoft). However, the Reclaimer symbol (a modified version of the Marathon logo) appears on the GEN2 version of the helmet in Halo 5: Guardians.
 * The Halo Encyclopedia (2009 edition) erroneously states the Security armor was manufactured in 2543 rather than 2528.
 * During the development of Halo 5: Guardians, the GEN2 Security armor was designated "A067" when it was conceived.

List of appearances

 * Halo 3
 * Halo: Blood Line
 * Halo: Reach
 * Halo 5: Guardians
 * Halo Mythos
 * Halo: Outpost Discovery
 * Halo Infinite