contact in PM's, i learned that using this not too long ago, i had bought a new ro/di, but it didnt have the restrictor in it, and i was mad and i posted it, the guy was at my house w/in 20 minutes to take back his ro/di, and tried refunding me my money....i really made a mistake by putting him out there like that...but needless to say this ro di works fine now after i bought a valve for it, thank god cuz the filters are all brand new...he spent over 100 dollars in filters and chraged me less for the unit itself....he did this so i wouldnt have to run all the time for water and i didnt realize this untill after i posted him out there like that....sorry mo...remember that mo...there i go again....hes a good guy, very experienced and knowledgeable, i trust what he says and does