Part of the Conqueror's Battlegear set:

The set gives these bonuses as more pieces are worn: 3: Decreases the rage cost of all Warrior shouts by 35%. 5: Increase the Slow effect and damage of Thunder Clap by 50%. Set Details | All Sets

Disenchants into

Name	Value	Drop%
Nexus Crystal	1 Copper	100.0%