According to Kabbalah, the Star protects the person who wears it.
Size of Pendent: 3cm /1.16 inch
The Star of David or Shield of David (Magen David in Hebrew) is a generally recognized symbol of Jewish identity and Judaism. It is named after King David of ancient Israel, and its earliest known communal usage began in the Middle Ages alongside the more ancient symbol of the menorah. Geometrically it is the hexagram.