Arms of Throwing

Aerodynamics. While wearing these construct bracer sleeves, all weapons you are proficient with gains the Thrown (Range 30/90) property, as long as they do not have the Heavy or Two-Handed property. You may use this range instead of other ranges of thrown weapons. If you Attack using a type of weapon you have the weapon mastery of, while using the Thrown property from this item, you may only use the Slow weapon mastery property instead. 

Improvised Aerodynamics. You have proficiency when attacking, specifically throwing, Improvised Weapons. The base damage is instead 1d6 damage of an appropriate damage type.

Notes: Proficiency: Improvised Weapons