External water tanks is optional to meet different need and assure ample water-supply. Whole plastic shell with high-strength, avoid rusting and keep clean, to meet GLP standard. 2 door and easy-to-replacing cartridge design, convenient to maintain system and replace cartridges. Tube and adapter with NSF authorization and top quality, reduce TOC level and assure ultrapure water´s quality. Optimized pretreatment (including PP fiber, KDF and active carbon cartridge), effectively protect RO membrane. RO module with DOW´s membrane, ensure long life, stable operation and high desalinization rate. DOW´s top polishing resin, ensure ultrapure water´s quality up to 18.2 MΩ.cm, with the lowest TOC level. Double wavelength (185&254nm) ultraviolet lamp module, restrain bacteria´s increase and reduce TOC.