From Halopedia, the Halo wiki
The helmet has a wide-range tracking feed, and a Q9L-3 Kotka comm-viel for transmission masking. The helmet is also one of the few that can fit the heavily classified ZILANT comm suite needed to access ONI's various hidden microsatellite constellations.
The suit has a ingress cloaking module to mask motion silhouettes at most spectrums. The reactor pack has a hardened uplink node for off-world communication.
INFILTRATOR-class Mjolnir, was manufactured by Hannibal Weapon Systems and was tested in the WG/Facility 93-00/Kotka. It was also tested on the orbital battleclusters above New Carthage, where Spartans were jettisoned and were forced to use re-entry packs to reach heavily protected weapon platforms, infiltrating them to accomplish specific objectives and escape without being hindered by passive inhibitors or guards.
Another INFILTRATOR prototype, notably different in form, was developed in the skunkworks departments of ANVIL Station. It experimental intrusion suites developed by the station's collaboration teams that could quickly applied to cross-generational platforms.
Some Spartans prefer the suit for its less opaque stealth systems over other systems.
In the Halo: The Master Chief Collection version of Halo 3, the Infiltrator variant was added as part of Season 6: Raven content. The set originates as one of a number of cut permutations from the cancelled Halo Online. During the original Halo Online game, Infiltrator was known "Demo" in a build before the closed alpha and later changed to "Saboteur" in the Alpha. With the updated Halo 3 armor customization options, the players can now fit their Spartan with Infiltrator helmet, chest, shoulders, forearms and legs. The description of the armor pieces are the same for every set.
Despite being introduced in Season 6, the armor was first shown off in the Season 5 Trailer.
Infiltrator was first introduced into the Halo games as an armor set in Halo 4. The armor has two available skins: Trace (TRAC) and Python (PYTN). As with all Halo 4 armor, the skins were not included in the initial release of Halo: The Master Chief Collection, though the release of Halo 4 on PC and the start of Season 4: Reclaimer saw the skins added into the collection as default unlocks - including the previously Champions Bundle-exclusive Python skin. In the original Halo 4 release, Python was unusable in Spartan Ops like all Champion's Bundle content, though this issue has been fixed for The Master Chief Collection.
Halo 5: Guardians
The Infiltrator returns in Halo 5: Guardians. The helmet and body armor are unlockable as armor permutations through the Requisition system. The body armor includes the Infiltrator chest and shoulders, an unknown set of forearms, and Recruit legs. The Infiltrator set only has one alternate skin; Saboteur.
List of appearances