In clothing, the term double-breasted refers to a coat or jacket with wide, overlapping front flaps and two parallel columns of buttons or snaps; by contrast, a single-breasted coat has a narrow overlap and only one column of buttons. In most modern double-breasted coats, one column of buttons is decorative, while the other functional. The other buttons, placed on the outside edge of the coat breast, are either decorative (non-functional) or functional, allowing the overlap to fasten reversibly, right lapel over left lapel. To strengthen the fastening, a functional inner-button, called the jigger, is usually added to parallel-fasten the over-lapped layers together from the inside.