Mezuzah Case

A Mezuzah is a piece of parchment contained in a decorative Mezuzah case and inscribed with specific Hebrew verses from the Torah. These verses consist of the Jewish prayer Shema Yisrael.
a Mezuzah is affixed to the doorpost of Jewish homes to fulfill the mitzvah (Biblical commandment) to “write the words of God on the gates and doorposts of your house”

(from Wikipedia)