A fetterlock is a semi-circular manacle, put on a horse’s ankle to prevent it from running away. It is open (unlocked) by Society default. While the bolt mechanism may be either to chief or to base in mundane heraldry, the most common attitude is with bolt to base, as in the Yorkist badge of the fetterlock-and-falcon, used since Edward IV [Hope2 169, HB 97]; this is the Society default. For related charges, see padlock, shackle.
Mons von Goarshausen bears: Per pale gules and sable, three closed fetterlocks Or.
Nikolai Jagger bears: Per chevron gules and sable, a fetterlock within a bordure argent.
Marsle Lokart bears: Azure, a closed fetterlock argent and in chief three hearts Or.