These Tefillin Dakkot are made by stretching a thin layer of parchment over a structural base and are made from one piece of parchment, which is Halachially preferable. The 33mm boxes of these Tefillin Dakkot are known to be of higher quality, to be more durable and larger than those of Tefillin Peshutim Mehudarim.
The Tefillin are Kosher and proofread by an expert as well as by a computer. The Tefillin come with a certificate proving the proofreading as well as a certificate proving the Kashruth level of the Tefillin. The Tefillin come with a ten year warranty.