older osmonics brand ro has 1-1/2 hp supply pump 5 hp tonkaflo high pressure pump has 4- 4inch membrane tubes 8 membranes total put new xle membranes and used for three seasons works great but have out grown loved this unit enough i replaced with the exact same thing but larger rating sticker says 9.3 gph perm and 1.4 gph conc which makes it 642 gph total will do more if you dont push that hard i ran conc. flow at 3.5 gph and recirculated till i got to percent that i wanted never pushed hard asking $6000 obo feel free to message me or call 814-964-1124