Sterling Silver Kabbalah Pendant Physical and Spiritual Balance by HaAri
One one size are engraved the names of the 12 Tribes, on the other, the names of the Choshen Breastplate stone names.
Inside the pendant is a paper containing a prayer from Rabbi Nachman of Breslav called the "heartbeat prayer". This is said to help mental and physical harmony, good for all smooth functioning of the body.