Tefillin, also called phylacteries, are two boxes containing Biblical verses and the leather straps attached to them which are used in traditional Jewish prayer. They are an essential part of morning prayer services in Orthodox and Conservative Judaism, and may be used in other branches of Judaism as well. They are laid on a daily basis (except the Sabbath and festivals) by traditional religious Jewish men above the age of 13 years,. According to Orthodox Jewish religious practice, only men lay tefillin. Most Conservative Jewish sources support all Jewish adults (both men and women) laying tefillin.