I'm kind of confused. Here's a panel from an issue of Invincible Iron Man. It has many armors there but what armor's the big one in the middle. It looks like a lot of ones I've found but i'm not definite.        

That's his super hydrolic neck armor. It's for super hydrolic headbutts.

Kinda looks like his Prometheum Armor

The armor pictured is not any of the previously seen armors. Keep in mind for every general purpose and specialty armor he ends up using, there are any number of prototype suits that never make out of the lab.

The armor pictured is not any of the previously seen armors. Keep in mind for every general purpose and specialty armor he ends up using, there are any number of prototype suits that never make out of the lab.

@batflasharrow96: I don't know but he is currently using it to fight mandarin

or some sort of a prototype or custom version of it