A:The pre-treatment system, ultrafiltration system, RO membrane element, ultrapure water system, dosing device, softened water system(Raw water tank, raw water pump, sand filtration device, carbon filtration device, softening device, various filter materials, precision filters, control valves, salt tanks, medicine tanks, metering pumps, flow meters, ultrafiltration filters, RO membrane elements, membrane shells, EDI modules, etc.) and related accessories involved in the reverse osmosis water treat