There are Many things that can render Tefillin or Mezuzah not Kosher or at best minimally Kosher.
Some of which happen over time with aging and some unfortunately are Posul from the get go.
Letters, words and or Tagim that are missing, extra substituted, touching, Broken, Improperly Spaced, misshapen faded, cracked and weather damaged.
We document the problems we find and periodically upload them to the website.
We hope that this will educate and encourage the public to purchase only Tefillin and Mezuzas that are high quality from a reputable source, to take care of them properly and have them checked regularly.
The number one reason why I tell people not to buy a Mezuzah in a Jewish museum gift shop or even a Judaica store. The Mezuzahs are almost always very poor quality. And more often then not blatantly not Kosher.
A Mezuzah is not to be compared to a Menorah or a Seder plate, who can blame a untrained sales clerk or Judaica owner from knowing any better. A Mezuzah is a specialty item and must be very specific and accurate to be Kosher and therefore must be purchased from a certified trained Sofer.
How many letters in this Mezuzah can you actually decipher?
Rabbi Kass was ordained by Rabbi Yisrael Meir Lau, former Ashkenazik Chief Rabbi of Israel. He is certified as a Sofer for both Kesivah and Hagoah by one of the leading experts in Safrus, Rabbi Avrohom Tzvi Vosner, Rav of the Vad Mishmeres Sta”m.