Construction engineering machinery manufacturing. Production, sales and technical research and development of electromechanical equipment, special equipment and accessories (excluding those requiring pre licensing and those prohibited and restricted by the government); Wholesale and retail of instruments and meters, communication equipment, building materials, steel, wires and cables, and hardware products; Import and export of goods or technologies (except those prohibited by the state or involving administrative approval); Metal and electrical welding processing services (excluding items requiring pre licensing, prohibited and restricted by the government). (Projects that must be approved according to law can only be operated after being approved by relevant departments)