a long black coat that chassidim are known for wearing on shabbat

A bekishe is a long coat, usually made of black silk or polyester worn by Hasidic Jews. Most Hasidim only wear them on Shabbos, Jewish holidays, or at weddings and other such events. During the week, most Hasidim wear a rekel, which is made of wool or polyester, looking like a regular double-breasted suit, only longer.