• Circlet of True Sight
• Item Level 219Disenchants into:
  [Abyss Crystal]: 1-2
• Binds when picked up
  
• Mail
• Head
• 1056 Armor
• +70 Agility
  +95 Stamina
  +54 Intellect
• Meta Socket
  Blue Socket
• Socket Bonus: +8 Critical Strike Rating
• Durability 85 / 85
• Requires Level 80
• Equip: Improves hit rating by 60.
  Equip: Improves critical strike rating by 42.
  Equip: Increases attack power by 156.
• 
• Sell Price: 9 19 61

Source

This item drops from Assembly of Iron in the 10-man version of Ulduar.

Patch changes

• Patch 3.1.0 (14-Apr-2009): Added. 
  

External links

• Battle.net (EU)
• Wowhead
• Thottbot
• WoWDB