what is it called, the headress Bishops wear, but not the crown, the black long-draped one?
Klobuk: a combination in the Slavic Churches of a cylindrical hat and attached veil. It is part of the habit for the Lesser Schema. You can see pictures on istok.com where they can be purchased. As to why some wear it and some don't during liturgical services, that I leave to our Orthodox and Eastern Catholic brethren to answer.
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