Kolpak (hat)
Kolpak (Ukrainian and Rusyn: Колпак) is an octagonal, onion-dome–shaped, segmented and collapsible hat, sometimes topped with a decorative cross, traditionally worn by Byzantine Catholic diocesan clergy of the Ruthenian and Ukrainian Greek Catholic Churches.
It is intended primarily for outdoor use. It is typically made of black cloth for lower clergy, while archpriests (or monsignors), canons and bishops wear a version made of amaranth or violet colored fabric.