metallic building materials, namely, heating, ventilation and air condition ducts and heating, ventilation and air condition duct fittings of metal or substantially of metal, with and without seals, dampers, connectors and metallic suspension means for said goods

metallic building materials, namely heating, ventilation and air condition ducts and heating, ventilation and air condition duct fittings of metal or substantially of metal, with and without seals, dampers, connectors and metallic suspension means for said goods