In earlier Talmudic times, tefillin were either cylindrical or cubical, but later the cylindrical form became obsolete. Nowadays the boxes should be fashioned from a single piece of animal hide and form a base with an upper compartment to contain the parchment scrolls. They are made in varying levels of quality. The most basic form, called peshutim ("simple"), are made using several pieces of parchment to form the inner walls of the head tefillin. The higher quality tefillin, namely dakkot ("thin"), made by stretching a thin piece of leather, and the more durable gassot ("thick") are both fashioned from the single piece of hide.
