The first test batch of the armor, designated X-01 Mk I, was developed for Presidential bodyguards, and served as the baseline for the remnants of the United States military, who developed it into a power armor tailored for the post-War wasteland. The development of the first suit of advanced power armor, designated X-01, began shortly before the Great War. 2.5 Advanced power armor Mark II (Tesla variant).2.3 Advanced power armor Mark I (Tesla variant).
