They were hand-crafted by Kar Vastor out of ultrachrome he found in the jungles of Haruun Kal, possibly remnants of the Jedi starship that brought the Korunnai ancestors to the world in the Great Sith War. The shields were immune to the metal-eating jungle rot of Haruun Kal and also, as superconductors, could not be cut by a lightsaber; however, if a lightsaber was held to the metal long enough, it would melt. They also could deflect blaster and slugthrower bolts.
In addition to acting as a shield, they had sharp edges that could be used to cut an enemy. They were equipped with simple electronics that allowed them to vibrate ultrasonically, for additional cutting power.