Now, why didn't anyone think of this before? This ingenious product from Tefillin Beit E-l is a flexible protective cover for the Tefillin Shel Yad. It does not interfere with the Yud knot, even allowing it to stand upright. Attaches to the Bayit and does not fall off. Protects the corners of the Tefillin, and there's no need to remove before making the Blessing.