[Source] Beskar'kandar was a type of Mandalorian armor comprised of plates forged from beskar iron, a near-indestructable ore found only on the planet Mandalore and its moon, Concordia. The beskar used in the armor's construction made it almost impervious to the blows of a lightsaber. However, the Sith Lord Darth Bane—who wrote a brief passage on beskar'kandar armor in an essay entitled The Rule of Two—found the armor to be extremely heavy, and noted that any Sith who may consider utilizing the Mandalorian armor should adopt a Strong or Djem So stance while in combat.