• Rifle of the Platinum Guard
• Item Level 219Disenchants into:
  [Abyss Crystal]: 1-2
• Binds when picked up
  
• Gun
• Ranged
  
• Speed 2.80
• 289 - 537 Damage
• (147.5 damage per second)
• +42 Stamina
• Durability 90 / 90
• Requires Level 80
• Equip: Improves hit rating by 24.
  Equip: Improves critical strike rating by 29.
  Equip: Increases your armor penetration rating by 31.
• 
• Sell Price: 15 32 85

Source

This item drops from Ignis the Furnace Master 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