Processing of mechanical parts and components; sales of mechanical parts and components; manufacture of railway locomotive and rolling stock parts; sales of railway locomotive and rolling stock parts; manufacture of railway special measuring or testing instruments; sales of railway special measuring or testing instruments; manufacture of power electronic components; sales of high-speed rail equipment and accessories; auxiliary activities for railway transport; sales of rail transit engineering machinery and components; sales of lighting fixtures; manufacture of general equipment (excluding special equipment); sales of power electronic components; retail of hardware products; sales of electrical equipment; manufacture of pneumatic and electric tools; sales of pneumatic and electric tools; manufacture of urban rail transit equipment; sales of instruments and meters; sales of office supplies; sales of labor protection supplies; sales of security equipment; sales of mechanical equipment; sales of lubricating oil; repair of general equipment; sales of rail transit special equipment, key systems, and components; technical services, technology development, technology consulting, technology exchange, technology transfer, technology promotion.