19th century, square, bronze or brass, astrological plaque or amulet showing a concentric mandala surrounded by a square border of the twelve, animal zodiac calendar.  The reverse side is embossed with a four sided, dorje symbol.  These amulets were carried and worn by individuals to protect them from evil forces.  It measures 4 1/8" by 3 1/2" wide and weighs 240 grams.  This was part of an estate sale that I will be listing similar, antique items from so be sure to check back.