I am trying to connect an under counter Reverse Osmosis ( R.O. ) filter inlet line (red 1/4" tubing) to the cold water supply line (3/8" black tubing in picture) under my kitchen sink.
Can anyone help me figure out what sort of Tee/adapter fitting I need to get this done?
Obviously I still need the black cold water supply line to feed the sink faucet as well as this red R.O. Filter inlet line.
I also want the shut-off valve to be in the line to the R.O. filter.
enter image description here
Additional pictures here showing sizes of connections: https://i.imgur.com/WViRYcs.jpg https://imgur.com/1W8dRrq.jpg https://imgur.com/M18gamH.jpg