Charlie’s Cybernetic Arm is a weapon in Kingsman: The Golden Circle.
First Arm
When Charlie met Poppy Adams and became a member of the Golden Circle, he received a cybernetic arm and vocal cords.
While in a car chase across London, he was propelled from Eggsy's Black London Taxi, his first robotic arm was severed from him. It was later controlled remotely to hack into the Kingsman Database, which then sent a collection of missiles to the location of every Kingsman Agent, leaving only Eggsy and Merlin alive.
Second Arm
As a reward for Charlie, Poppy gave him a new arm, “Arm"-ageddon, equipped with many new weapons and tools, even allowing him to propel the hand forward. It has enough power to throw a bowling ball with enough force to break a wooden wall.