METAL BUILDING MATERIALS, NAMELY, TUBES, TUBULAR RODS, RODS, STRUCTURAL PANELS, IN PARTICULAR STRUCTURAL PANELS FOR WALLS, FLOORS, CEILINGS FACADES AND COVERING PANELS; CONNECTING PIECES OF METAL FOR BUILDING, NAMELY NODE AND STRUTS AND WEIGHTS-BEARING PIECES OF METAL FOR BUILDING, NAMELY, STRUTS; TRANSPORTABLE BUILDINGS OF METAL IN THE NATURE OF SPACE FRAMEWORKS; TRANSPORTABLE BUILDINGS OF METAL NAMELY, SCAFFOLDINGS, ROSTRUMS AND STANDS SERVICING AND MAINTENANCE STANDS AND FRAMEWORKS FOR AER...