Construction engineering design, various construction engineering activities. General items: sales of rail transit engineering machinery and components; manufacturing of special railway measuring or testing instruments; development of rail transit communication and signal systems; research and development of mechanical equipment; manufacturing of high-speed rail equipment and accessories; sales of high-speed rail equipment and accessories; processing of mechanical parts and components; sales of mechanical equipment; leasing of mechanical equipment; retail of hardware products; manufacturing of railway locomotive and rolling stock accessories; sales of railway locomotive and rolling stock accessories; technical services, technical development, technical consultation, technical exchange, technical transfer, technical promotion.