The Mezuzah
No, it’s not a Jewish doorbell. It’s a home security device called a mezuzah, and it’s wired into the Ultimate Protection Agency.
The software inside this gadget is a scroll with the words beginning, “Hear OIsrael, the L‑rd is our G‑d; the L‑rd is one.” Those powerful words sum up the mandate of a Jew: to infuse the world with G‑d’s oneness.
Regarding these words, G‑d has commanded us, “And you shall inscribe them on the doorposts of your home, and on your gates” (ibid., verse 9). Hence the mezuzah: a parchment scroll inscribed with the verses of the Shema-prayer is affixed to the right doorpost of every room in a Jewish home
Read More Main Article link:
http://www.chabad.org/library/article_cdo/aid/278460/jewish/Guide.htm
How Mezzuah Is made:
http://www.beingjewish.com/mitzvos/mezuzah.html
Questions And Answers About Mezuza:
http://www.mezuzah.net/sofer.html
Small Video:
http://www.chabad.org/multimedia/media_cdo/aid/1020939/jewish/The-Mighty-Mezuzah.htm