• Greaves of Swift Vengeance
• Item Level 239Disenchants into:
  [Abyss Crystal]: 1-2
• Binds when picked up
  
• Mail
• Feet
• 931 Armor
• +69 Agility
  +55 Stamina
  +49 Intellect
• Red Socket
  Blue Socket
• Socket Bonus: +6 Agility
• Durability 70 / 70
• Requires Level 80
• Equip: Improves hit rating by 42.
  Equip: Improves critical strike rating by 42.
  Equip: Increases your attack power by 114.
• 
• Sell Price: 10 34 48

Source

This item drops from Assembly of Iron on hard mode in the 25-man version of Ulduar.

Patch changes

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

External links

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