Suits of course, but they mandatorily are carting around a Heavy Weapon. It's pretty unfortunate for Skirmishers, though, albeit it takes a bit to be noticeable a flaw since Heavy Weapons aren't available initially. Notably, this means that the resistance classes introduced in War of the Chosen can never equip Heavy Weapons, since they're stuck with their medium-derivative unique armors, though to be fair Reapers and Templar don't particularly notice the lack. Suit -the heavy set of armors- provide the wearer a slot for equipping a Heavy Weapon.
They're clearly in some sense derived from Heavies in the previous game having a rocket launcher, but they're not tied to class or anything like that, yet they're also not a general-access Item type.