Abstract: A border unit comprising a front panel (3) and a foot (4, 5) which when standing on a flat horizontal base surface supports the front panel (3) vertically with the bottom edge of the front panel (3) extending along the base surface. The unit (20) has end surfaces (21, 22) which are adapted to support each other around at least part of the cross section periferi of coaxially joined unit (20). Each unit (20) has at one end (22) a vertical rod (7) and at the other end (21) a recess which receives the rod (7) of an adjoining unit (20), to form a coupling (7, 11) for joining units. The coupling is located in a central part of the unit cross section; the end surfaces of the unit has a straight generatrice which is parallel to the rod and vertical when the unit stands on a horizontal base surface.