The suit was modified as the successor to Mich's previous armor. Unlike the prior, the Mark II contains more fluid abilities, allowing Mich to dash out of the way of gunfire as well as clambering onto edges, as well as 3 different types of meters; the top is cooldown, the middle is the shield, and bottom is health (same goes for Agent California's new armor).
The Mark II also contains a fail-safe, preventing others or enemies from using it if their biometrics don't match.
LN4R Mark II Evolved
The evolved version of the armor, which is used in FR Season 8, is more powerful and adaptible, allowing him to also use his cybernetic abilities as well.