The Flexi-Armor, Model IV, Mark I, made its debuted in TALES OF SUSPENSE #85. Known as “flexi-armor,” the materials in this suit made it flexible and lightweight, but still tougher than any before—making Iron Man more invincible than ever. While Model IV could withstand mighty blows and was impervious to small bore machine guns, it was still vulnerable to the Melter’s rays. The armor mesh is wafer thin and extraordinarily flexible, but his movement stretches it taut, and that’s a great deal of its strength. It should also be pointed out that this model was form fitting. While Stark’s later armors were sculpted and machined to produce a very buff-looking Iron Man (see the Silver Centurion and others), the muscles seen on this Iron Man are Stark’s actual muscles showing through. Which is not to say that Tony’s strength was Iron Man’s strength. No, Iron Man was assisted by powerful transistors that drove the supremely compact armatures that were his mechanical muscles. On-board computers even calculated the degree of force to apply when IM punches or flexes to bend something.

But this suit’s real power comes from just that: more power. Stark doubled the natural capacity available to the suit with a radically new energy-induction matrix coupled with a new transistor design. (At the same time, he also improved the overall efficiency of his armor’s systems.) As a result of the new energy systems, mere wall outlets couldn’t charge him fast enough. Iron Man now relied on an energy induction matrix capable of absorbing energy in greater amounts—and much, much faster. Now, a special pair of energy beams in his lab provided IM with a massive dose of power, recharging him in seconds whenever he needed it.

Flight was accomplished by air jets in the boots, now equipped with a “turbo” feature. Via a small control stud on his right shoulder cuff, Shellhead activated built-in booster rockets, kicking his boot jets up a notch.

Aided by his improved chest device, Stark’s heart was now stronger than ever, but that didn’t stop him from including an emergency booster supply. Stored in his right wrist compartment, the booster was a safeguard for his heart. In addition to the heart devices, the armor’s life-support functions included an internal oxygen supply for brief underwater action.

The armor’s heat induction knob—the right “nipple,” if you will—activated imbedded circuitry in the armor’s surface, heating it up enough to free Iron Man from frozen blocks of ice.

The suit could also protect an unconscious hero. The release pins on the mask are pulsed with an electric current to provide a shock to anyone attempting to remove Iron Man’s mask.

Special Feature on this Suit: By turning his earpieces, Stark activated jet skates.These jet wheels took less energy than flying, but they also came in handy for quick, dizzying maneuvers on the ground. Armaments: Repulsors (could be adjusted to deliver an ultra-frequency dose capable of knocking a person unconscious or concentrated into a thin, high-pressure, laser-like beam); Chest beam (capable of beaming light or energy weapons); Electro-Stun Ray (fired from chest beam; manually switched on by turning the rim of the beam; can electrify foes’ weapons); tiny Explosive Pellet (stored in right shoulder epaulet; delivers huge explosion); battery-operated Image Reproducer with Sound Duplicator (could make up to five duplicates appear to confuse opponents). As with all technological wonders, the Flex-Armor eventually became obsolete. Technology always moves forward and soon the once the miracle transistors Tony depended on became outmoded as a source for powering his armor. The future was in integrated circuits. And that’s just where Tony went.