Semi-Powered Infiltration armor

Manufacturer | Various
* Watershed Division
* Ushuaia Armory (Mk II AIR ASSAULT)
 Affiliation | * United Nations Space Command
	+ Orbital Drop Shock Troopers
	+ Office of Naval Intelligence
	+ Spartan Operations

"*Part legionnaire mail, part tactical body armor, and part chameleon.*"
―Kurt Ambrose
The **Semi-Powered Infiltration armor**, usually abbreviated to **SPI armor**, is a stealth-optimised brand of power armor that is primarily utilized by SPARTAN-III supercommandos. An independent venture organised by Colonel James Ackerson, SPI is aimed to compete with the far better known MJOLNIR PAA even while using assets originally intended for its rival project. Shedding half the weight of its predecessor, SPI is known for its adaptive camouflage system, capable of cloaking its user to a point that they cannot be seen at a range further than 100 meters.

## Specifications

### MIRAGE-class Helmet

One of two parts of the armor not created in-house by Ackerson's group, the MIRAGE-class helmet was originally developed by the Materials Group as an alternate variant for MJOLNIR. Undergoing some modifications to ensure it is fully compatible with all of the SPI's features, the helmet remained visually identical to its original model. Nearly half the helmet is dominated by an immense visor which covers nearly all of the user's vision, made out of crystal glass to remain tough while still being completely transparent. Both sides of the glass are coated with a thin sheet of aluminum, with the outermost layer given a reactive lacquer which changes color based on the voltage flowing through it. The lacquer also contains impurities which absorb radiowaves, although the other electromagnetic waves are reflected back away from the user. Micro-projectors mounted along the rim of the helmet are used to project relevant information onto the visor at the user's whim.

The MIRAGE-class helmet would later be used as a baseline for the Mk II and III SPI variants, as most helmet variants would borrow many design features from the MIRAGE-class.

### Variants

#### Air Assault (AA-variant)

The **AIR ASSAULT** variant of the SPI Mk II system is designed for speed and toughness, being utilized by Spartans being deployed from the air, as the name suggests. The armor shares many similarities with its MJOLNIR counterpart, with both being manufactured by Ushuaia Armory. The AIR ASSAULT variant includes many hardpoints to anchor gear to, designed specifically to survive any landing, intentional or otherwise. Its lightweight and flexible design allows the user to transfer momentum from the landing into forward motion during an assault.

Due to its overspecialization, it is one of the least used variants of the SPI system. However, it is still used by not only its intended users, but also by commanders and other specialists. However, as it has many similarities with the standard ODST BDU, many ODSTs have elected to use AIR ASSAULT as their variant of choice.

Tyler-A319 used AIR ASSAULT for a short period of time.

#### Grenadier (G-variant)

The **GRENADIER** variant of the SPI Mk II system is built around strength and toughness. Despite its name, its use is not limited to grenadiers or demolition specialists.

Mark-G313 wore the GRENADIER variant during Operation: JOVIAN WHISTLE.

#### Hellbringer (H-variant)

 File:Rayne SPI.png
The **HELLBRINGER** variant of the SPI Mk II and Mk III systems

The name HELLBRINGER is a misnomer, as neither the suit's purpose nor its appearance are shared with the suit worn by Hellbringer flamethrower teams. Users of the HELLBRINGER armor are known to stylize their gear and weapons to match those of the flamethrower teams, including painting fire or animal heads on their rifles.

#### ??? (K-variant)

The **K-variant** of the SPI system was a classified project being developed under close watch by Section Three of the Office of Naval Intelligence. Not much is known about the project, as the development of the armor was postponed indefinitely sometime prior to 2548 and all research was reclassified as top secret. Only a select few of individuals have knowledge beyond just its existence, including Office of Naval Intelligence Head Serin Osman.

#### Operator (O-variant)

The **OPERATOR** variant of the system is a variant designed for optimization and efficiency by Chalybs Defense Solutions. Originally designed in parallel with the MJOLNIR variant exclusive to Beta-Five's Asymmetrical Action Group members, the SPI variant soon gained popularity in other fields, including mechanics and combat medics.

The armor is incredibly energy-efficient, able to power its photoreactive panels, shields (if equipped with any), communications, NAV equipment, and sensors, as well as multiple external systems, continuously in the field with acceptable power drain. The suit also includes many hidden storage spaces for equipment such as first-aid kits, small biofoam containers, and even some explosives.

The OPERATOR variant does have downsides, however. It has less than optimal heat regulation systems, reduced armor, and limited sensors. However, the suit does make up for this with increased maneuverability.

The Headhunter Roland wore the OPERATOR variant.

#### Pilot (P-variant)

The **PILOT** variant of the SPI Mk II system is a variant designed alongside its MJOLNIR equivalent.

#### Responder (R-variant)

The **RESPONDER** variant of the SPI Mk II and Mk III systems is designed for recovery of assets in hostile or otherwise hazardous locations. It is equipped with multiple redundant data retrieval systems to ensure the user can receive intel necessary for asset recovery, a CBRN system for harsh environments, and multiple communication systems to contact live assets in the field or to communicate with command.

The armor is extremely lightweight to give the user increased mobility in dangerous situations. However, this reduction in armor means that the user is prone to injury or death if they are not careful.

Kyle-B115 wore the RESPONDER variant throughout his entire career.

#### EVA (V-variant)

The **EVA** variant of the SPI Mk II system

#### Whisperer (W-variant)

The **WHISPERER** variant of the SPI Mk II system

Luke-G249 wore the WHISPERER variant.

## Known Users

* Spartan-IIs
	+ Class-I
		- Kurt-051 (Mk II)
	+ Class-II
* Spartan-IIIs
	+ Alpha Company
		- Robert-A057 (Mk I)
		- Shane-A112 (Mk I)
		- Jane-A203 (Mk I)
		- Tyler-A319 (Mk II AIR ASSAULT)
	+ Beta Company
		- Adam-B004 (Mk II)
		- Lucy-B091 (Mk II)
		- Kyle-B115 (Mk III RESPONDER)
		- Min-B174 (Mk II)
		- Tom-B292 (Mk II)
	+ Gamma Company
		- Holly-G003 (Mk II)
		- Ash-G099 (Mk II Standard)
		- Dante-G188 (Mk II)
		- Luke-G249 (Mk II WHISPERER)
		- Olivia-G291 (Mk II Standard)
		- Mark-G313 (Mk II GRENADIER)
	+ Headhunters
		- Jonah (Mk II Standard)
		- Roland (Mk II OPERATOR)
		- SPARTAN-G059 (Mk II Standard)
* Non-Spartans
	+ ODSTs
	+ ONI Personnel
		- Veta Lopis (Mk II Standard)
		- Zachary Rayne (Mk III HELLBRINGER)