MJOLNIR
From Halopedia, the Halo wiki
Summary
Origins: Thor, the Norse God of Thunder and Lightning, possessed a powerful weapon, a hammer that was able to control storms. It's name is Mjolnir, which means "lightning".
Note: Pronounced "mole-near".
Marathon
The Mjolnir Mark IV Battle Armor was in Marathon...
Halo
Mjolnir Mark V Battle Armor is designed for the SPARTAN II program. Each is custom fit for every soldier. The suits are designed to be compatible with all the enhancements the SPARTANS have, including a neural interface so they can control the suit with their thoughts and keep an AI in the suit; and increased strength and durability. The Mark V suit was the first MJOLNIR suit to feature energy shields. Only SPARTANS can use the armor because the suit is too strong for a normal human body to handle; it ripped the testers' limbs off just from moving. The suit has a small fusion core as its source of power and a integrated rechargable shield system.
In Halo 2, Master Chief's Mark V suit was replaced by a Mark VI suit. This suit has superior shielding systems and a different HUD display, and also apparently (because it is not outright stated) has integrated Biofoam insertors, removing the need for medical packs, for replenishing health, that the Chief had in Halo: CE, since he regains health automatically as his shields recharge. Obviously, this sets up the possibility of yet another suit being made. This is interesting because the next type would logically be a Mark VII, which would coincide with the frequent appearances of the number seven.
Images
http://img245.echo.cx/img245/6742/mjolnirshield1ht.jpg
