This is an image from the internet showing a soldier wearing Tefillin.

Every adult male from 13 onwards is required to bind his arm and hand with Tefillin as a part of morning prayers.

Tefillin consists of two small leather boxes called Bayit* attached to leather straps. The two boxes contain passages from the Torah** expressing assurance of reward that will follow observance of God's laws, warning of retribution for disobedience to them and acts of God that must be remembered.

*Bayit in modern day Hebrew also means Home.

** In Judaism, he law of God as revealed to Moses and recorded in the first five books of the Hebrew scriptures (the Pentateuch).