The following description was prepared by William Gross:
A mezuzah (Hebrew: מְזוּזָה "doorpost"; plural: מְזוּזוֹת mezuzot) is a piece of parchment (often contained in a decorative case) inscribed with specified Hebrew verses from the Torah (Deuteronomy 6:4-9 and 11:13-21). These verses comprise the Jewish prayer "Shema Yisrael", beginning with the phrase: "Hear, O Israel, the LORD (is) our God, the LORD is One". In the mainstream, i.e. Rabbinic Judaism, a mezuzah is affixed to the doorframe of Jewish homes to fulfill the mitzvah (Biblical commandment) to inscribe the words of the Shema "on the doorposts of your house" (Deuteronomy 6:9). Some interpret Jewish law to require a mezuzah on every doorway in the home apart from bathrooms and closets too small to qualify as rooms. The parchment is prepared by a qualified scribe who has undergone many years of meticulous training, and the verses are written in black indelible ink with a special quill pen. The parchment is then rolled up and placed inside the case.
The mezuzah in Algeria consisted of a decorative piece, often of silver, mounted on a thick piece of wood. A niche for the parchment was hollowed out in the back and the whole assemblage was hung on the wall, inside the house. The motifs of the temple implements and the menorah were very popular in this area, most often on Shiviti plaques.