General items: Manufacturing of refrigeration and air conditioning equipment; Sales of refrigeration and air conditioning equipment; Household appliance installation services; And development of mechanical equipment; Manufacturing of environmental protection special equipment; Sales of environmental protection special equipment; Manufacturing of fans and ventilators; Sales of fans and ventilators; Of general equipment (excluding the manufacturing of special equipment); Repair of general equipment; Manufacturing of metal products for safety and firefighting; Manufacturing of ordinary valves and plug valves (ex the manufacturing of special equipment); Research and development of valves and plug valves; Manufacturing of glass fiber reinforced plastic products; Sales of glass fiber reinforced plastic products; Manufacturing of hardware products wholesale of hardware products; Manufacturing of dust removal technology equipment; General mechanical equipment installation services; Sales of mechanical equipment; Sales of electrical equipment; Sales of mechanical and electrical equipment; Repair electrical equipment; Sales of plastic products; Sales of pumps and vacuum equipment; Sales of valves and plug valves; Sales of bearings; Import and export of goods. (Except for that must be approved by law, carry out business activities independently according to the business license. )