Reverse osmosis takes place within its system. This a configuration of RO components that maximises the efficiency of this process to produce purified water. The most basic system will include a membrane, a housing to accommodate this, and a valve on the concentrate (waste) feed to create back pressure within the system. This back pressure is what forces water molecules through the tiny pores of the semi permeable membrane. More developed systems utilise pressure booster pumps and different types of gauges and meters to fine tune its operation and output.