Firearms play a large part in Adan. Few people would argue on the raw destructive power of a firearm in the hands of a trained gunman. So it has become a common tactic of arcane users to remove such weapons either out of the holster or out of the hand of experienced gunmen.
Inevitably these mundane gunmen (often bounty hunters) have countered this tactic with an invention of their own.
A simple cord (or fine chain) loop is attached to the butt of the firearm and looped over the shoulder and around the body. Many different styles exist. But the function is the same a cord the keeps the firearm from being pulled away from the gunman.