Quadrone (4e Feat)
From D&D Wiki
At some point you were a four-armed quadrone, and have retained their ability to dual-wield bows.
Prerequisite: Modron, Dexterity 13
Benefit: You treat shortbows and longbows as one-handed, off-hand weapons. When you wield a shortbow or longbow in each hand, you gain a +1 bonus to damage rolls of weapon attacks that you make with a ranged weapon. If such an attack would use an arrow, you expend an additional arrow.