● Flow restrictor purpose flow restrictors (also known as Flow controls or Capillaries) are required for all reverse osmosis systems ● It is recommended that the flow restrictor is replaced each time an RO membrane is replaced in order to keep your system working at optimum performance, as scale build-up can occur and clog the capillaries ● RO-FR is made by food grade plastic only, Enogh strong to pressure membrane waste and smooth to save RO membrane from blockage