Rabbi Klein gave the Bochurim a crash course in Tefillin making from start to finish.
He had many samples and taught various halachos as they were being passed around.
It really gave the Bochurim a better understanding and appreciation for Tefillin.
The Bochurim also learned about The "Klaff" used for ספרי תורה, and learned many halachos about writing the letters.
rabbi klein then passed around a Part of a torah written on deer hide! (Which was done in Spain).
It was truly engaging.