Sale of mechanical equipment; wholesale of hardware products; retail of hardware products; sale of building materials; leasing of mechanical equipment; manufacture of metal materials; sale of metal materials; import and export of goods; import and export of technology; installation services for general mechanical equipment; manufacture of specialized environmental protection equipment; sale of specialized environmental protection equipment; manufacture of general equipment (excluding special equipment); manufacture of machinery for construction engineering; sale of machinery for construction engineering; manufacture of agricultural machinery; sale of agricultural machinery; manufacture of metal fittings for construction; sale of metal fittings for construction; manufacture of electronic measuring instruments; sale of electronic measuring instruments; manufacture of specialized equipment (excluding licensed specialized equipment); repair and maintenance of motor vehicles; technical services, technical development, technical consulting, technical exchange, technology transfer, and technology promotion. Licensed items: basic telecommunications services; first-class value-added telecommunications services; second-class value-added telecommunications services; production of road motor vehicles.