The metal ring was placed around the victim’s neck and the screw tightened until the metal teeth were placed below the chin. Then the victim was hoisted into the air, usually with the toes just touching the floor, the teeth of the necklace biting into the chin and neck.
Trivia & Comment
A similar version existed in China in which the prisoner’s head was stuck through a hole in the top of a sturdy wooden box, the feet barely off the ground.