Heretic fork

A device that often looks like a collar with a double ended fork attached. It is placed between the collarbone so that the pointed 'fork' ends in the middle of the chest and under the chin. The modern device can commonly be adjusted in size and is held in place by a strap around the neck of the recipient. The goal is to make the recipient bend their heads back and make it uncomfortable/impossible to move the head forwards. It can also impede the ability to speak, swallow or open the mouth. Sometimes Posture Clothing can have this device included, but this is fairly rare.

Origins

Originally created as a torture device for witches and heretics it was meant to punish and sometimes to get a confession out of the person wearing it. These confessions possibly resulted in a conviction. In some cases it had "I renounce" or "I refuse" in the language of the time written on it as a symbol of the punishment (source).