Tefillin are two black leather boxes containing four biblical passages written on parchment which are bound by black leather straps to the forehead and left arm (or in left-handed people, the right arm). Tefillin are traditionally worn by men during morning services every day except Shabbat (Saturday morning) and holidays. The tradition of wearing Tefillin comes from four different verses in the Torah, each of which speaks of a "sign upon your hand and a symbols between your eyes' (Exodus 13:9, 13:16 and Deuteronomy 6:8, 11:18). 
For more information about tefillin, *click here*.
This guy is right-handed:
