Brotherhood T-51b Power Armor

The Brotherhood T-51b power armor is a piece of armor in Fallout: New Vegas.

Characteristics
Brotherhood T-51b power armor provides a damage threshold of 25 as well as a bonus of 1 to Strength and +25% Radiation resistance. It can be repaired with T-51b power armor and T-45d power armor. You must have Power Armor Training in order to wear this armor.

This armor acts as a Brotherhood of Steel disguise, which will make NCR personnel hostile towards you (Unless you have peacefully completed the Brotherhood section of For the Republic, Part 2).

The armor is fitted with a back-mounted TX-28 MicroFusion Pack which generates an output power of 60,000 Watts to power the HiFlo hydraulic systems built into the frame of the suit. Made of a poly-laminate composite, the outer shell of the T-51b is lightweight and capable of absorbing over 2500 Joules of kinetic impact. The 10-micron-thick silver ablative coating can reflect laser and other radiation emissions without damage to the composite subsurface, and the eyeslit for the helmet is made of bullet proof glass to protect the wearer from any projectiles. The armor usually carries enough fuel to last for one thousand years.

Locations
You can find it on dead Brotherhood of Steel members in the Still in the Dark quest: Note: Its almost impossible to pickpocket it, even with a sneak skill of 100 or a stealth boy.
 * Two can be found just outside the Nellis Air Force Base. You can find while avoiding the artillery shells flying at you; or gain entrance to Nellis then come back and search in relative safety.
 * Two can be found on the third floor of the REPCONN Headquarters. You'll find two downed Brotherhood of Steel members, one under a  fallen chunk of ceiling, the other against the wall, a few feet from Piers Isley's Briefcase.
 * Two can be found in a radioactive crater east of Hidden Valley (If you only find the body of the dead paladin with the logs, the other body probably glitched into the wall). About 5 centaurs are in and around the crater including a bigger centaur called Moe.
 * Four more can be looted from dead Paladins depending on how you finish Veronica's quest, I Could Make You Care.
 * Can be obtained from Hidden Valley if the player has the Mister Sandman perk and kills sleeping paladins. (Doesn't turn any BOS characters hostile)
 * It can be pickpocketed from Head Paladin Hardin If he becomes Elder as he will not wear it.

Bugs

 * Brotherhood T-51b power armor is much more common than intended, due to the armor occupying a list meant to hold Brotherhood T-45d power armor. Among other issues, this results in the dead paladins found in the quest Still in the Dark being attired in T-51b armor, rather than the intended T-45d armor.
 * A third-party bugfix for this issue can be found here: New Vegas Nexus. This fix is also included as part of the Community Bugfix Compilation.
 * Sitting on a bench or couch while wearing the armor will cause the shoulder guards to move out of place. Similar to other Power Armor such as the T-45d Power Armor.
 * After declaring peace between the Brotherhood and the NCR, regular soldiers will not attack you with the armor on, but Rangers will "see through your disguise" and attack you.
 * The NCR will attack you if you wear this armor but doesn't seem to care if Veronica is wearing it and Major Knight at Mojave Outpost will even repair it for you.
 * If you give Boone this armor while wearing it a pop-up screen with an OK button will appear, similiar to if you play New Vegas on a PC with a mouse, telling you that you're not longer dressed as a member of the Brotherhood Of Steel with no way to exit.