Kaf כ for kippah, or yarmulke (כיפה)
Why do Jews wear a kippah?
A head covering is a sign of respect and humility. Therefore, men wear a kippah at times and in places where they commune with God, such as:
during prayer and blessings
reading the Torah
while being in the synagogue and the house of study (yeshiva)

Wearing a kippah is not a religious commandment, but a tradition. Many Jews wear it daily.

• • What customs do you know that express respect in religious places?
• • Do you know other clothing items that are worn out of tradition? 

Symbolism:
The Hebrew letter כ (Kaf) corresponds to the number 20.
Symbolic meaning: outstretched hand, to open.