Picked from the corpses of undead soldiers, the Undying Plate seems to be normal plate armour. When worn however it has some interesting effects.

You have a +1 bonus to AC while wearing this armor, but for every hour worn, the player suffers one day of exhaustion. 

Shields require the Utilize action to Don or Doff. You gain the Armor Class benefit of a Shield only if you have training with it.

Notes: Disadvantage: Ability Checks, Exhaustion, Combat, Warding