A prospective tefillin buyer recently sent in the following question regarding the types of tefillin we sell:
I’m doing some research before I buy my set of tefillin, and I was wondering what the difference is between the dakkot ones and the dakkot ohr echad?
Physically, the Tefillin Dakkot are slightly larger than the Tefillin Dakkot Ohr Echad and the finishing work is slightly superior.
In terms of halacha, the Dakkot Ohr Echad are superior. According to halacha, the Shel Rosh must be made of a single piece of leather (“ohr echad“). Among the Rishonim and Achronim there are various opinions as to what that requirement means.
1) Some say even various pieces of leather glued together (known as “Tefillin Peshutim”) are considered ohr echad.
2) According to other opinions the primary part of the Shel Rosh, known as the bayit, must be ohr echad, and then attached to the tatura (the base) and the maabarta (the back part of the base where the strap passes through).
3) According to stricter opinions, all three parts of the Tefillin Shel Rosh must be ohr echad. Almost all Tefillin Gassot today are ohr echad according to this definition.
Tefillin Dakkot Ohr Echad are made like the regular Dakkot, and then a very thin piece of leather is placed around the entire Shel Rosh, which gives it the status of ohr echad according to the stricter opinions.
However, keep in mind that all Tefillin Dakkot are easily damaged and are very difficult to repair, therefore if you have the means it is generally recommended that you invest in a set of Tefillin Gassot, which are very durable, an asset that generally pays off over time.