Hello, I need a suggestion on how to connect a water pressure regulator to my tap water source. The pressure regulator has an odd type fitting that doesn't match up to my water source. (see photo #1). Detail: I bought a new reverse osmosis unit. My home water pressure is almost 100 PSI, but the recommended water pressure for the RO unit is 65 PSI, hence the pressure regulator. The short of it is that the regulator has 1/4" MIP female fittings for it's inlet and outlet. I wanted to connect the regulator to the cold water shut-off valve located under my kitchen sink. (See photos #3 & #4). My plan was to replace that existing cold side valve with a brand new one that has two male 3/8" OD (compression) fittings, exactly like the hot side currently does, (see photo #5). My plan was that one of the two outlets on the new valve will supply the cold side of my kitchen faucet, while the other outlet will go to the pressure regulator's "IN" side. (3/8" OD to 1/4" MIP). The out side of the regulator is good as I found a fitting that will connect the regulator to my RO unit, (see photo #2 with the red tubing attached). I went to Home Depot looking for an adapter 3/8" OD to 1/4" MIP, but there ain't no such animal. My shut-off valve for the kitchen faucet connects via a female 1/2" NOM compression fitting, (shown best in photo #3). The other side of the that fitting is soldered onto the copper coming from the wall. If you can think of any way for me to bring the pressure regulator in-line with the water system then please let me know. I am pretty much stuck unless I force a wrong thread fitting into it with a bunch of glue. The regulator is made of plastic. Also I only want to regulate the RO unit, nothing else. ============================================== #1 Water Pressure Regulator, showing the 1/4" MIP fitting. #2 Water Pressure Regulator with fitting attached for the down side flow to RO unit. The outlet is good. I just need to connect the inlet to a water source. #3 The cold side valve that's going to need to be replaced. #4 Full shot of the cold connection as it currently exists: #5 Hot Side. My original plan was to replace the cold valve with this same type of valve: Thanks for thinking about this. I appreciate it!