JFO-class Mjolnir

The MJOLNIR Powered Assault Armor/J variant, colloquially known as JFO or Joint Fires Observer, is a variant of the MJOLNIR Powered Assault Armor manufactured by Beweglichkeitsrüstungsysteme.

Design details
The JFO design was engineered with the goal of allowing lone Spartans to have improved communication when deep behind enemy lines, allowing them to better conduct cross-branch artillery request communication/coordination by Spartans across the Army, Navy, and Marine Corps. Spartans fielding the JFO suit are typically deployed with regular firearms and equipment, though are usually also outfitted with the latest targeting hardware in systems such as the H-165 target locator or its successor. Target designators are smart-linked to the suit's onboard technology suite, allowing the user to make quick and decisive air strikes in the field.

The helmet is compatible with the Type O5 up-armour module and Model 990101-1 FLAMINGO hardened uplink.

Development history
JFO was developed by Beweglichkeitsrüstungsysteme at the Special Warfare Center Essen. It was considered an "ill-favoured" entry into MJOLNIR development, but the JFO helmets were ultimately one of its most successful entries. As late as 2560, the GEN1 JFO could still be requisitioned by Spartans, upgraded to be roughly equivalent to GEN3.

Usage
JFO was often fielded by single Spartans in reconnaissance, infiltration, and artillery targeting scenarios behind enemy lines. In 2553, the JFO helmet was worn by SPARTAN-III Owen-B096 as part of his mission with Outpost Discovery.

Halo: Reach - GEN1
"Designed and tested at Beweglichrüstungsysteme this helmet is fully compatible with all armor systems."

The JFO helmet appears in the armory upon reaching the rank of, but is not unlocked until.

The helmet features a large visor, shaped like a shield or a fattened "T", and has two small air intakes on the cheek areas. Overall, the helmet provides significant armor coverage, protecting the majority of the head while maintaining a large field of vision.

In-game, the HUL-I is available only for the JFO helmet. The shoulder pieces are semi-circular arches that jut outwards from the shoulders. They also feature black, two-pronged protrusions that point parallel to the arm, and away from the hands.

Halo Infinite - Upgraded GEN1
The Mark V JFO helmet and its attachments are available for multiplayer Spartan armor customization on the Mark V [B] armor core in Halo Infinite. The JFO shoulders are available under the SAP series of shoulder pads.

Trivia

 * JFO stands for Joint Fires Observer, a United States military designation for troops who coordinate fire support from land-based artillery and naval gun formations, as well as close air support.

List of appearances

 * Halo: Reach
 * Halo: Lone Wolf
 * Halo: Outpost Discovery
 * Halo: Meridian Divide
 * Halo Infinite