Flowmatic Watts FM110015M 50 GPD Reverse Osmosis Membrane for WP-5. Reverse Brine Seal. For Watts and Flowmatic manifold systems. Do not use in the standard Watts or Flowmatic systems as the reverse Bribe Seal will not function correctly. TFC high flow. We recommend replacing the flow restrictor located in the end of the drain line hose where attached to the system. Remove the tube and find the flow restrictor and discard. Install our new inline flow restrictor in the drain line by cutting the line about 12" from the system. Order 2 and save even more!