Tefillin phylacteries, are leather boxes filled with Torah verses on the Unity of God, the Exodus, and mitzvot. They are worn during morning prayers, except on Shabbat and Holidays. Tefillin boxes fare crafted from molded leather; their straps are also leather; Upon its parchments are the handwritten verses. All elements are held to a very precise specifications, so one should only purchase tefillin(a single lifetime purchase) from a trusted source—like Judaism.com, who only sells pre-checked Tefillin and Mezuzahs from its most reliable sources in New York and Israel.