
In this case it's less that the suit of armor weighs only 7kg and more that the flak armor you're wearing is comparable to only having 7kg of kit if it weren't comfortably distributed. Being fair, I could see the mechanical representation argument as well. The secrets of the maufacture of Terminator Suits are known only by a few, so the ones that remain are very valuable and old and are reserved for use by only the most highly trained brethren of the elite Space Marine Chapters. The immense power of the Terminator Suit means that troops using it can wield the heaviest weapons without restiction, handling autocannons and missile launchers like an ordinary man would handle an autogun or a bolter.

These support the gauge plasteel and ceramite plates which form the outer carapace. The armour itself is massively bulky so it contains a full exo-skeleton of fibre bundles and adamantium rods. Tactical Dreadnought Armor or Terminator Armor as it is more commonly known, is the best personal armour in the galaxy. It also commonly includes numerous auxiliary systems such as communications, auto-senses etc. Power armor is fully sealed to provide protection against gas weapons and harsh atmospheres. It is made from thick ceramite plates and would be heavy and cumbersome but but for electrically motivated fibre bundles implanted in the armor that replicate the movements of the wearer and the supplement his strength. The Power Armor is a completely enclosing suit of armour as worn by Space Marines.

Flak armour is mainly used by the Imperial Guard. Flak armor is cheap and easy to produce, requiring a very low technology base. Flak armor comprises several layers of different ablative and impact absorbent materials which should absorb the majority of energy from a shot.
