2st Stages in the Purecom Prisma Station: The reverse osmosis (RO) membrane is a semi-permeable membrane with pores of 1/10,000 of a micron. Water passes through it from a higher concentration solution (saline water) to pure water using pressure from the pump. RO is used to remove excess salts, viruses, bacteria, and heavy metals from the water. The post-carbon filter improves the water's taste and color, removes chlorine, and makes the water crystal clear. This product is Subject for delivery and installation policy Please review the policy. click her