Increases Product Water Output Includes All Components for Install Comes with a AquaFX 100 GPD Membrane Comes with the 100 GPD Flow Restrictor The AquaFx Piggyback Membrane Kit adds a 100 GPD (Gallons Per Day) membrane to any RO or RO/DI system with 1/4 inch tubing. This will increase your production and efficiency. Includes clips to attach the piggyback to your existing membrane and comes with all fittings, tubing and a brand new AquaFX 100 GPD membrane.