metal building materials, namely, closures and air transfer elements; transportable buildings; posts; non-electric cables and wires of common metal; ironmongery, namely, small items of metal hardware, namely wire clamps and band clamps; rigid, semi-flexible and flexible tubes and pipes of metal; goods of common metal, namely, union couplings and joints for pipes and tubes in the form of sleeves, muffs, flanges, flange sleeves and flange muffs; ventilation installations; metal chimneys and met...