Abstract: Disclosed is a flexible coupling whose operative interposition between communicating members affords the relative relationship of 360.degree. rotation, axial alignment, misalignment, offset relationship, articulation at different angles axially. The flexible coupling is self-cleaning and acts as a vibration dampener. The flexible coupling has upstream and downstream collars which mount a U-shaped annular flexible member whose one end portion is fixed to the upstream collar between an annular flange and keeper plate and whose other end portion is freely retained on the downstream collar between annular flanges.