It represented a radical, new approach to designing powered armor, eschewing traditional armor design philosophies, but was never deployed in larger quantities until the 23rd century. 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).

This is all extremely convoluted I'll admit but nonetheless I'll make 2 implementation versions just to give options on how people want it to coincide with lore. So unless there's a MK.II armor we haven't seen yet, it just wouldn't make sense that the X-01 is anything but a renamed and retconned Mark.II. It wouldn't make sense that there was no mention or sighting of the Mark I in Fallout 3 on the east coast, and then suddenly in Fallout 4 the Mark II (that was ubiquitous in Fallout 3) is gone and only a retcon of the Mark I remains, even though it had no presence on the east coast in Fallout 3. It's confirmed by Protector Casdin that the (Fallout_3) was the enclave model featured in Fallout 3, the Mark I, as it was seen in Fallout 2 (and Fallout: New Vegas) was not featured in Fallout 3, so the only assumption to be made is the MK.I was effectively phased out by the time the Enclave reached the east coast. The reason I find this relevant is because the other power armor designs are perfect to almost every detail. The on the other hand, has mirrored symmetrical hoses on either side of the helmet, has no cylindrical hepa filter in the cheek, and no hoses going into the 'cheek' of the helmet. On the left side of the forward-facing helmet the has a large hose going into the cranium, and a large corrugated hose that come round the side of the helmet and goes into the 'cheek', and on the right side cheek it has a cylindrical HEPA filter, and the right side cranium has twin hoses that wrap around the side. Just from my own observations, the X-01 lacks the asymmetrical helmet design that the MK.I has, and the helmet is quite a lot more compact. Josh Trembly Posts: 3381 Joined: Fri 9:25 am They've done a very close job of replicating the appearance of the T51b and the T-45d, but the X-01 has a lot of differences between, leading me to believe it's probably not the same one. It'll probably be 'lore-friendly' standalone version, and a separate replacer version for people who want the X-01 stats and a model replacement. This is being built to coincide as essentially an older obsolete model of the X-01, I'll give it stats that lie inbetween the X-01 and the T60 to indicate that it's an improvement over pre-war models, but surpasses by the the MK.II and other later enclave armor variants (on the possible assumption that the X-01 is entirely new) The name 'X-01' is probably just a rename to bring it in line with the likes of 'T-51' and 'T-45' name format. As I said, the one seen in Fallout 2 is the MK.I. The one in the game is likely a retcon of the MK.II APA that's in Fallout 3.

Fallout 4 enclave power armor mod