Housing Membrane RO (Reverse Osmosis)-Drat 1/8 "-Micron water Filter- Vacant-Housing to accommodate the membrane RO (CSM, Filmtec, Pentair, etc) to a size of 50, 75, 100, 150/LP gpd. -In-lid that can be opened > to insert RO membrane: drat in the 1/8 ". -Out-1 Middle > ex. clean water filtered RO: drat in the 1/8 " -Out-2, next Out-1-output > wastewater filtered drain/RO: drat in the 1/8 " -FITTINGS for connecting the hose to the 1/4 "is not included, can be