Metal mezuzah

Mezuzah is a talisman of the home and placed on the doorpost at the entrance. 
The text of the mezuzah is written with special ink which is called in Hebrew, "Dieu". The recipe for their manufacture is transmitted from generation to generation and has been received of Moshe (Moses) from God on Mount Sinai. 
By reinforcing the mezuzah on the doorpost, Jew enlists the Divine protection.