Manufacturing and processing of doors and windows; engineering construction of metal doors and windows; sales of doors and windows; sales of metal products; wholesale of hardware products; retail of hardware products; sales of fire-fighting equipment; fire-fighting technical services; design and construction services of safety technology prevention systems; sales of mechanical parts and components; sales of mechanical and electrical equipment; sales of building decoration materials; research and development of new material technology ;Technical services, technology development, technical consultation, technology exchange, technology transfer, technology promotion; import and export of goods; technology import and export; sales of metal materials; sales of metal structures; sales of valves and cocks; sales of glass fiber reinforced plastic products; sales of wires and cables; sales of lighting equipment; sales of labor protection supplies; sales of electronic products sales; sales of chemical products (excluding licensed chemical products); sales of building materials; manufacturing of rubber products; sales of plastic products; sales of building ceramic products; sales of daily ceramic products; wholesale of kitchenware, sanitary ware and daily sundries; sales of sanitary products and disposable medical supplies; sales of paper products; sales of lamps; sales of household products; home furnishings Sales of electrical appliances; retail of electronic components; sales of knitted textiles; retail of clothing and apparel; retail of shoes and hats; sales of communication equipment; sales of office equipment; sales of office supplies; sales of furniture; wholesale of auto parts; retail of motorcycles and spare parts; wholesale of bicycles and spare parts; sales of lubricants; sales of refrigeration and air-conditioning equipment; sales of daily necessities