Manufacturing, processing, sales, installation, maintenance, and technical research and development of marine supporting equipment, general mechanical equipment, vehicle parts, plastic products, and molds (excluding rubber products); Metal processing; Sales of metal materials, hardware electrical appliances, daily necessities, building decoration materials (excluding paints and coatings), and standard parts; Self-operated and agent import and export of various commodities and technologies, except for commodities and technologies restricted or prohibited by the state.