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The Vault - Fallout Wiki
Stealth suit Mk II
Stealth suit Mk II.png
Icon assassin suit.png
9 (JS)14
Item HP500
EffectsAll of the effects stack:
Sneak +15 (Firmware v1.0)
Sneak +25 (Firmware v1.1)
Perception +1 (Firmware v1.2)
Agility +1 (Firmware v1.3)
Movement-speed while crouched +20% (Firmware v1.4)
Combat armor
Medium armor
QuestsX-13: Attack of the Infiltrator!
Project X-13
base idxx00c12f
Dialogue FileStealth suit Mk II's dialogue
Gametitle-FNV OWB.png
Gametitle-FNV OWB.png

Hello. It's nice to meet you. Who can I hide you from today?

— Aural Stealth Suit on-board operating system

The Aural stealth suit[1]Mk II, referred to by Dr. Klein as the psychoanalytic cardiac-dampening sneaky stealth suit , is a unique piece of medium armor in the Fallout: New Vegas add-on Old World Blues.


Created by Big MT researchers in the X-13 research facility using captured Chinese stealth armor technology as a basis, the aural stealth suit was supposed to be a next generation, cutting edge infiltration suit, to be used in the war effort.[2] After the proof-of-concept suit was completed, work began in earnest on an actual prototype. While the first unit was merely a standard suit of armor, built to test the validity of the pattern, the Mark II became a unique, computerized platform, combining the best technologies available to Big Mountain.

The core element of the suit is a central control system located in the torso, which controls the built-in medical dispenser, capable of injecting Med-X and stimpaks automatically, provides real time feedback on battlefield conditions, automatically fits the suit to the user's shape and frame[3] and automatically adapts systems to the user's specifications during testing and unlock features as they come online (though since it never left the testing phase, the control system requires the user to complete infiltration tests in the X-13 research facility), based on an ingenious firmware upgrade created by researcher Kael.[4] These upgrades are necessary for the user to benefit from the more advanced subsystems, such as gloves coated with a rubberized dampening compound to enhance manual dexterity[5] or advanced servomotor buffers in the leg rigs, allowing for faster sneaking.[6]


The suit has a similar design to the assassin suit, but is cleaner and has a luminescent white chest piece with similar white stripes on the back. The suit itself has a built-in medical system that dispenses Med-X and stimpaks automatically. A female-voiced on-board computer narrates the usage and current levels of these items, as well as warning of impending combat situations, reminding the player of an active Pip-Boy light, and making off-hand comments without prompting. The computer is very similar to, and just as talkative as, the personality modules given to the Light Switches in The Sink.

The suit can be upgraded in the X-13 testing facility to provide an additional 10 to Sneak, for a total of +25. Further upgrades include a +1 Perception, +1 Agility, and even a 20% sneak speed bonus when worn. When poisoned by a cazador, the suit will dispense a stimpak if available and cure the poison while also increasing your health.


The suit can be upgraded in the course of four stealth tests in the X-13 facility. Bonuses from upgrades are cumulative.

  • Firmware version 1.1 - Has a bonus of +10 to Sneak (Stacks with the +15 sneak already on the armor, giving +25 to sneak).
  • Firmware version 1.2 - Adds a bonus of +1 Perception.
  • Firmware version 1.3 - Adds a bonus of +1 Agility.
  • Firmware version 1.4 - Adds a bonus of +20% to Stealth movement speed.


Name DT WG Durability Value Armor class Effects
Assassin suit 14 20 500 7500 Light armor +10 Sneak
Stealth suit Mk II 14 25 500 7500 Medium armor All of the effects stack:
Sneak +15 (Firmware v1.0)
Sneak +10 (total +25) (Firmware v1.1)
Perception +1 (Firmware v1.2)
Agility +1 (Firmware v1.3)
Movement-speed while crouched +20% (Firmware v1.4)

Notable quotes

  • "You're my best friend forever!"
  • "We haven't seen anybody in a while... maybe the monsters have stealth suits too."
  • "Sneaky sneaky."
  • "Stealth Boys are a robot's biggest weakness."
  • "Pipboy light's on."
  • "Shhh...we´re very stealthy."



  • The stealth suit is considered a medium-type armor, meaning you are slowed a bit by wearing it (this slowing effect is largely negated by the bonus to sneaking speed when the suit is fully upgraded). You also have to find other medium armors to maintain the suit with Jury Rigging or repair it with standard combat armor.
  • Unlike the prototype medic power armor from Fallout 3, the Med-X dispensed by the suit is regular Med-X, which the player can become addicted to.
  • Stimpaks used by the suit are not affected by Medicine level.
  • The suit will be sure to mention any time you are sneaking with the Pip-Boy's light on.
  • If your health is low, the suit will use a stimpak, and will continuously do this until your health reaches an adequate level. In hardcore mode, the suit checks to see if there are any restore health effects first, if not, it then administers a stimpak.
  • When unequipping the suit from a companion, it still plays an audio comment as if the player was wearing it.
  • Despite being a medium armor and acquiring the upgrades, the stealth suit Mk II has the same value as the assassin suit.
  • The increase in crouch speed effect is done through a perk, called Stealth Suit Mk II, instead of a object effect like the others.

Behind the scenes

  • The on-board computer is voiced by Qore hostess Veronica Belmont, who also voices The Sink's light switches, and the original unaltered voice of Christine Royce.
Icon cut content.pngThe following is based on Fallout New Vegas cut content and has not been confirmed by canon sources.
  • There remains several unused assets for a vision effect that would have allowed the player to see in the dark, albeit with a blue tint over the screen, when crouched. Oddly, all the assets appear to be in place but are not associated with anything, but the scripts point to a quest called NVDLC03StealthSuitVisionQuest which isn't in the GECK. It is possible there wasn't enough time to implement the quest for the final version of Old World Blues and it had to be cut.
Icon cut content.pngEnd of information based on Fallout New Vegas cut content.


  • PCIcon pc.png Xbox 360Icon xbox360.png There is a bug where after the suit auto-applies a stimpak your health will not increase; keeping your health at the minimum threshold for the damage script. This causes the suit to use a stimpak every time you're injured, as you drop below the scripted HP, burning through stimpaks extremely quickly.
  • PCIcon pc.png Before starting the stealth research in X-13 make sure all armor pieces are in your inventory. Starting the run before the pieces are taken may bug the script and result in not getting the armor.
  • PCIcon pc.png The stealth suit seems to occasionally glitch out, and continuously issue doses of Med-X until the user's supply has been emptied, or until the suit is taken off (Leading to Med-X addiction very quickly).
  • Xbox 360Icon xbox360.png When fully upgraded, it doesn't seem to boost your sneak speed by the said 20%.
  • Xbox 360Icon xbox360.png In third-person view, rotating to the front side of your character can sometimes cause the head and arms of the player character to disappear, immediately reappearing once the camera returns to the rear.



  1. Mobius: "You think that Aural Stealth Suit will keep you hidden from me? Think again!"
    (Mobius' dialogue)
  2. Nightstalker research in X-13 ran concurrently to the stealth suit's development, and was also intended for the war effort
  3. X-13 research facility terminals#Test Area A - Review
  4. X-13 research facility terminals#Mk II Torso_Research
  5. X-13 research facility terminals#Mk II Glove Research
  6. X-13 research facility terminals#Mk II Boot Research