About: Third Arm Weapon Interface System

The Third Arm Weapon Interface System, or Third Arm, is a passive, stabilizing device developed by the U.S. Army Research Laboratory (ARL) in 2016 to redistributes the weight of heavy firearms to make them easier to hold and carry. It weighs less than 1.8 kg (4 pounds), and consists of a mechanical appendage made out of carbon-fiber composite that has one end attached to a carbon fiber plate that fits inside an armor plate pocket and the other end attached to a Picatinny rail on top of the gun. It was to permit more accurate use of heavier weapons and reduce fatigue by displacing the weight of the weapon from their arms to their torso and mitigate firing recoil. As of 2018, the Third Arm is a prototype and is still in the testing phase of its development.