Technical services, technology development, technical consulting, technical exchange, technology transfer, and technology promotion; research and development of metal products; sales of metal wire ropes and their products; sales of metal products; sales of metal structures; sales of metal chains and other metal products; sales of metal materials; sales of plastic products; wholesale of hardware products; retail of hardware products; sales of railway transportation equipment; sales of railway transportation infrastructure equipment; machinery and equipment leasing; sales of building materials; sales of doors and windows; sales of electronic products; sales of machinery and equipment; sales of fire-fighting equipment; sales of security equipment; sales of household goods; sales of furniture parts; sales of textiles; labor services (excluding labor dispatch); import and export of goods (except for projects that require approval by law, independently conduct business activities not prohibited or restricted by laws and regulations).