Their work was efficient allowing the previous bindings pining their prisoner to the floor to be replaced with a set of more portable permanent shackles, from a distance the newly fashioned metal could be mistaken for oversized bracelets, but their function was to bind the captured limbs in whatever formation desired by anyone who wore the dark mark. As metal was melded painfully to bones, the knew there was no easy way for the prisoner to escape these bindings, short of amputating limbs.