The Wolf Rack have an A-frame structure that is manufactured from 2mm thick sheet metal. The frames have an open structure. The tops of the individual A-frames contain rivet nuts and are bolted into a U shape tie bar with self-aligning bolts while load bars are fitted into slots at the base of the A-frames on each side. The load bars are also fastened by self-aligning bolts screwed into rivet nuts, which are permanently fixed at base of the A-frames. This produces a rigid connection and allows assembly without special skills and only one tool.