The following description was prepared by William Gross:
From earliest times, man has tried to protect himself from misfortune by the use of objects which he considered holy or otherwise (e.g., magically) potent. Amulets and talismans are items generally worn around the neck or wrist, carried in a pocket or purse or hung on a wall. They are meant to protect or aid those who carried or wore them. The Hebrew word for amulet, kame‘a, has the root meaning "to bind". Jewish amulets are usually comprised of texts (either letters or graphic symbols) that are inscribed on some sort of material; some may also contain plant matter or precious stones. The texts of amulets usually include holy names that are believed to have the ability to affect reality, along with incantations summoning angels or other magical powers. For the most part, an amulet has a specific purpose: to ease childbirth, facilitate recovery from illness, improve one’s livelihood, and so on, but in the modern world many are also made for general protection.
There are more surviving silver amulets from Iran than from any other area. Within this large quantity of amulets, there are a number of distinctive groups of similar form. This type of small round amulet with a beaded rim and simple inscriptions of two or three words are from the Kirudistan area of Iran. Such amulets are often found as a central part of a more elaborate necklace as well. In this example there are three names only. The amulet has bells suspended from the bottom, whose noise may be another way of repelling evil spirits.
Inscription: Adonai Tzamarchad Shadai