The APAT Heavy Infantry unit uses APAT Heavy armour, a whole body encompassing armour that uses steel and a mix of ceramics to fully encompass and protect said soldier wearing armour. It has air filters, goggles, and lights to accompany and better protect the soldier's vitals. Even though it is extremely heavy, hydraulics and pistons help the soldier move easily in the armour, which also allows easy handling of heavy weapons such as miniguns and AT weapons. This entire air tight and powerful set of armour is powered by a pack of batteries that is armoured, which is carried on the back like a armoured backpack.
this is obviously inspired by fallout's power armour uhhhh ig me? imma redesign this abomination one day