Rabbi Yaron Reuven discusses the difference between Rashi and Rabbeinu Tam tefillin. Learn when a Jewish man should wear Rabbeinu Tam tefillin, and some basic laws of how and when to wear them. Rabbeinu Tam Tefillin are only for married men, and should be worn after the Rashi at the end of prayer, without a blessing. Rabbi Reuven also warns to be careful buying from sources that sell at a discount like ebay or Amazon, as usually they aren't kosher and saying a blessing on them would be a sin.