CIO-class Mjolnir

CIO-class Mjolnir (Counter Intelligence Operator) is a variant of the MJOLNIR Powered Assault Armor [GEN2] manufactured by Acheron Security.

Overview
The CIO helmet has a tricloptically fixed multi-spectral imaging array, also known as a transponder array. The neural interface bypasses in the CIO helmet allow the wearer to create custom synesthesis profiles to remap the suit sensors with their own senses. The suit also has a galvanized sensory suite that rivals nearly all other similar service packages.

The chest has a modular sensory suite, and a silhouette dampener for motion sensor circumvention.

Development history
After seeing the need for highly trained, heavily armored personnel to be deployed deep into enemy-controlled territory, Acheron Security developed and manufactured the CIO-class armor, with its main focus on espionage rather than lethality. The armor was tested at the Acheron Trauma Sim, and was designed to operate in the Martian territory of Acheron Fossae.

Usage
Though rarely seen, it is utilized by a handful of SPARTAN-IVs and Counter-Intelligence Operators for intel acquisition and strategic data conveyance deep within enemy territory, often those who endure tier-nine theaters.

Several CIO-armored Spartans were deployed to Terceira, where they captured and transmitted information crucial to the recovery of the colony from Insurrectionist forces.

CIO is also used during information denial missions, hunting down enemy scouts and preventing them from acquiring data of tactical or strategic importance.

Halo 4
Unlock: Spartan Slayer - Master commendation Available skins: WEB(Web), RUIN(Ruin) and RUSH(Rush)
 * Description: Designed for counter-intelligence operability in the Martian territory of Acheron Fossae
 * The WEB skin was a pre-order bonus through Amazon. It is also available in the Halo 4 Game of the Year Edition.
 * The RUIN skin is available as a DLC code packaged with the CIO-armored Spartan action figure in the second series of McFarlane's Halo 4 action figures. It is not usable in Spartan Ops.
 * The RUSH skin is included in the Champions Bundle. It is not usable in Spartan Ops.

Halo 5: Guardians
This armor set in Halo 5: Guardians permanently has the following
 * Forearms: Ricochet
 * Legs: Recruit

Unlock: Rare REQ card
 * Helmet Description: The neural interface bypasses in the CIO helmet allows the wearer to create custom synesthesis profiles to remap the the suit sensors with their own senses.
 * Body Description: CIO's niche is information denial missions: hunting down enemy scouts and preventing them from acquiring data of tactical or strategic importance.

List of appearances

 * Halo 4
 * Infinity Briefing Packet
 * Halo 5: Guardians