Sales of slide and projection equipment; Digital video monitoring system sales; Audio equipment sales; Software sales; Sales of radio and television transmission equipment; Wholesale of electronic components; Hardware wholesale; Domestic trade agency; Internet sales (except for the sale of goods requiring license); Sales of electronic products; Sales of power electronic components; Sales of household appliance parts; Sales of household audio-visual equipment; Retail of household appliances; Technical services, technology development, technical consultation, technical exchange, technology transfer, technology promotion; ; Technology import and export; Import and export of goods.