In Iron Man #1, Vol. 4, Stark uses an armor that is so similar to the one seen at the end of Iron Man, Vol. 3, that it must be considered the same suit (some editorial omissions and contradictions notwithstanding). So we’ll split the difference and call it PreExtremis Armor, Model Nil.
The this experimental unit--which looked essentially like the Pentagon Armor--was made of memory metals, which enabled it to be collapsable for storage into a briefcase (that could only be opened by the security lock chip located in Stark’s arm). An electric charge causes the armor to snap into shape and the molecular structure collimates into super hard planes. Most of the interior elements compress to about 90 percent of their working volume.
The PreExtremis Armor, is tougher, faster, and lighter than the Pentagon Armor. But Stark couldn’t miniaturize the control systems, so he needed the hard upper torso unit, the chestplate, and the helmet with its systems, which didn’t shrink much. Beneath the armor plating, Stark wore a golden techno-mesh suit. He can put on the armor manually, but also has an assembler machine to automate the process.
Note that this early version doesn’t have the belt cartridge and has round hip pods.
Stark made significant improvements to the helmet in this armor. For starters, he took his by-now-standard heads-up display (HUD) and went to the next level, developing a next-gen ocular motion reader for a sight-based system control. A spray of very low-powered lasers read changes in motion and pressure on the eye, telling the onboard computer what Tony was looking at. (The suit also responds to verbal commands.) Like with previous models, the mask plate flips up.
Another nice feature turned the helmet into a billion-dollar flash drive: there’s a retractable cord that could be used to plug the helmet into other computers (even when one has just the helmet).
Stark made significant leaps in his now patented repulsor technology. While the armor had rocket propulsion it now also featured a repulsor-based flight system. Iron Man could switch between the two depending on his needs.
This armor had the standard secondary systems and auxiliary power, including a thermocouple heat-inductive transfer field, which allowed IM to receive energy from fire and so on.
This suit had a full sensor array, including thermal imaging. It was packed with a robust communications suite. The eye lenses featured magnification abilities.
The PreExtremis Armor had a thorough medical program complete with an auto-activating emergency intervention system. The armor could inject the wearer with pain killers as needed.
Armaments: Repulsors (reactionless force projection [a one-way push]); screamers (a sonic weapon); chestbeam (triangular, it can also fire a laser for recording off of glass); tiny bomblets (launched from gauntlets).