A multi-sided bellows cover has panel sections formed of extruded plastic panels in which rigid wall sections are connected at the fold lines by flexible web sections. The web sections are integrally molded by extrusion with at least one adjacent wall section, and many serial wall sections alternating with web sections may be integrally co-extruded with one another. Intermittently, a bead of one of the flexible web sections of one of the panel sections is captured in a slot of one of the rigid wall sections of another panel section.