Offensive Security Unit

The Offensive Security Unit is an enemy in Xenoblade Chronicles that are members of the Mechon family. They can be found at level 56 at the Connecting Bridge on the Fallen Arm. They can also drop the Refined Part Ms, which are needed for the "Restoring the Capital 2" quest. A story variant is fought by Sharla, Reyn and Shulk at level 52 once they are reunited at the Ulna Passage on the Fallen Arm.

Chests rates

 * Wood = 77.6%
 * Silver = 19.4%
 * Gold = 3%

Wood

 * Materials
 * Refined Part M - 73.7%
 * Quality Jet - 26.3%

Silver

 * Cylinders
 * Phys Def Down IV - 31.3%
 * Initial Tension IV - 31.3%
 * Weapons
 * Prosperity Biter - 8%
 * Wolf Guarder - 1.9%
 * Draft Rifle - 1.6%
 * Cerasus Cutlass - 1.1%
 * Armors
 * Amethyst Boots - 16%
 * Brave Gloves - 3.7%
 * Stellar Gauntlets - 3.1%
 * Orion Bottoms - 2.1%

Gold
Advanced Books
 * Weapons
 * Jumbo Guarder (1 slot) - 8.8%
 * Jumbo Guarder (2 slots) - 7.3%
 * Snaer Striker - 4.9%
 * Unique Weapons
 * Century Staff - 18%
 * Dividing Line - 3%
 * Unique Armors
 * Inferno Armour - 22%
 * Earth Boots - 18.3%
 * Blade Boots - 12.3%
 * Play Dead - 2.4%
 * Anchor Chain - 1.6%
 * Gale Slash - 0.9%
 * Double Wind - 0.4%