History
This armor was created by Tony Stark shortly after the previous model was damaged beyond repair battling The Freak. This armor was not only more flexible, but also returned to a nose-less faceplate.[3] The armor later underwent several overhauls and was one of the longest models used.

James Rhodes replaced Stark as Iron Man for a considerable time using this armor. Happy Hogan, Eddie March, and Force also wore it on different occasions.
Despite having developed various more advanced armors since this version, Tony tends to default to a model of this armour when his modern suit has been destroyed or disabled and he lacks the time, resources or inclination to create a more advanced replacement. One example of this was when he destroyed his sentient armor and was afraid of creating a new, modern version in case he recreated the accident that gave his previous armor sentience.[4]
During the Siege of Asgard, Tony was given a modified version of the Model 4 by Jarvis, who sent Young Avenger Speed to give it to him, and he used it to override Osborn's Iron Patriot Armor.[5] Then, during the battle with The Void, Iron Man overrode the H.A.M.M.E.R. Hellicarrier and used it as a bullet to hit The Void, turning him back to Robert Reynolds before Thor killed him.[6]

When Tony Stark undertook Stark Resilient, he dismantled and melted one of the various models of this armor.[7]
Capabilities[]
Reed Richards praised the armor's sophistication and clear, straightforward design.[8][9] Its structure was improved with 3D knitting. In addition, a force-field helped keep the armor rigid.[3]
The armor used solar power (but recharged slowly without a large source of electricity),[10] and integrated micro-circuitry. A thermocouple was used to handle extreme temperature and convert it to usable power, but it could be overloaded.

Repulsors were standard weaponry. The variobeam/uni-beam was capable of various effects. A tractor beam could be used to pull or tow objects. The most recent version of the armor was able to use pulse bolts.[11]
Gyro-stabilizers were used in the boot jets.
Power pods were capable of various functions such as boosting other systems or being set to detonate.
ECM jamming was used to evade detection.

Assembled for the first time
A hologram emitter created multiple images to make the armor harder to target.
In addition to the sonic emitter, a voice distorter helped protect Stark's identity and could also be used to duplicate sounds.
The armor could travel underground.
Freon could be emitted and a built-in fire extinguisher handled internal and external fire.
Finger lasers and a "sabresaw" were available for cutting through objects.
Life support was improved; the pacemaker was no longer needed after successful heart surgery.
A slave circuit was added to control older suits after the incident with Weasel Willis. However, this was a weakness when Midas attempted to gain control of the armors.

Notes
- The 2008 "Iron Manual" states that Iron Man's Model 4 armor first appeared in Tales of Suspense #85, but this issue actually shows the creation of Model 3 MK II (unofficial designation). The Model 4 armor first appeared in Iron Man #85 and has more significant changes in function.
See Also
- 538 appearance(s) of Iron Man Armor Model 4
- 5 appearance(s) in handbook(s) of Iron Man Armor Model 4
- 160 minor appearance(s) of Iron Man Armor Model 4
- 4 mention(s) of Iron Man Armor Model 4
- 750 image(s) of Iron Man Armor Model 4