Basically armour, but with double the health and penetration resistance (can be rebalanced). Also wayyyy heavier than normal armour so that it can't be spammed and should only be used to protect key subsystems.
In singleplayer, crafting a hyper armour block should require rare materials. Due to its mass and cost, it will only be used in major starports only.
- But this is unbalanced and redundant!
It shouldn't be unbalanced. Its mass and price tag should mean that people won't be able to build basically invulnerable fortresses to drag out an MP game and the removal of 1x2 armour eliminates redundancy.
It should also give the casual players something to play around with (roleplay, for instance), and makes the construction of fully hyper armoured ships a possible singleplayer grinding target in its own right...