Unassembled Underworld Mainhand Weapon

Unassembled Underworld Mainhand Weapon is an Underworld gear token. It can be traded to a class Ultimate Gear Vendor on the Imperial and Republic Fleet for an Underworld mainhand weapon.

Source
Unassembled Underworld Mainhand Weapon is obtained from the Cartel Warlords in hard mode Scum and Villainy and from Golden Fury.

Gear
Unassembled Underworld Mainhand Weapon can be traded in for the following items: