Designer: Anthony Stark
Worn by: Kevin O'Brien, Michael O'Brien, Anthony Stark
Appeared: Iron Man #43

Design notes :

Shell Composition: Semi-rigid interior/3D knitted metallic exterior made of steel and steel alloys. Provided protection from physical attacks as well as heat, cold some energy forms and acid. A new 3D knitting pattern on a sub-molecular construction level gives the armor itself more strength, while allowing for the most comfortable suit interior including it's ability to collapse for storage. It uses a magnetic field to bring the armor into its rigid state.

Power Source and Energy Information: The armor ran on batteries and was able to recharge itself from electrical sources.

Control Systems Interface: Cybernetic interface and battle computer.

Weaponry:
Palm Repulsors: Laser guided partical beam emission units mounted in the palm of each hand.

Equipment:
Life Support Equipment: The eye and mouth hole slits could be sealed. The suit had an oxygen supply for 30 minutes.
Boot Jets: The boot jets are actually chemically fuelled thrusters.

Notes:  The Guardsman armor was designed as a back up for the Iron Man armor. The suit was given to co-worker and confidante Kevin O'Brien. Calling himself the Guardsman, O'Brien used the armor to save Iron Man, but faulty circuitry within the helmet affected his personality, turning him against the Golden Avenger. Kevin O'Brien died in an explosion while fighting Iron Man. Stark International retained the armor.

Kevin's brother Michael broke into the company months later and stole the armor, intent on investigating his brother's death, but the mood altering nature of the malfunction soon turned him against Iron Man as well. Iron Man managed to subdue Michael and correct the faulty component in the armor. Michael dropped his vendetta against Iron Man and saved his life in a battle against the mutant Sunfire. Iron Man gave O'Brien the armor in repayment.

When Stane took over Stark International, he mass-produced the Guardsman armor for the government. They are mainly used at the high-security penitentiary for super-powered criminals dubbed "The Vault".
  

Specs provided by Paul Livingston