The T-51 is the apex of pre-War powered combat infantry development. Developed over a decade of war by West-Tek, it incorporates many of the lessons gleaned from the T-45 power armor service history. Unlike its predecessor, the T-51 benefits from a long development cycle and uses custom-made components to create not a stop-gap model, but a weapon that provides the best possible protection through incorporating the latest passive defense features.

• Brotherhood T-51b Power Armor, a light gray version bearing the Brotherhood insignia and used by its Paladins in the Mojave chapter.
• Winterized T-51b Power Armor, issued to elite units during the Anchorage Reclamation.

• T-45d Power Armor
• Remnants Power Armor
• Enclave Power Armor