Development, design, manufacturing, installation, and sales of gearboxes for transmission systems; technical consulting services and after-sales service for gearbox systems; research and development, manufacturing, processing, and sales of rail transit equipment and vehicle parts; research and development, production, and technology transfer of aluminum alloy products; hardware products, mold manufacturing and processing; steel sales; self-operated and agent import and export of various commodities and technologies, excluding commodities and technologies restricted by the state for enterprise operation or import and export.