• Tempered Mercury Greaves
• Item Level 226Disenchants into:
  [Abyss Crystal]: 1-2
• Binds when picked up
  
• Mail
• Feet
• 903 Armor
• +57 Agility
  +66 Stamina
  +40 Intellect
• Yellow Socket
  Red Socket
• Socket Bonus: +12 Attack Power
• Durability 70 / 70
• Requires Level 80
• Equip: Improves hit rating by 48.
  Equip: Improves critical strike rating by 38.
  Equip: Increases your attack power by 138.
• 
• Sell Price: 9 59 11

Source

This item can be found inside Cache of Innovation after defeating Mimiron on hard mode 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