If you're going to install a Watts regulator, they sell them at HD. Tell the HD apron what you want to do and he/she will hook you up. If they give you the deer in the headlights look, ask for a mgr. They will get you the right person and parts. That said, I attach mine to the spigot, then run a short hose whole house filter attaching with a quick coupler. From the WHF the hose runs to the water softener and on into the coach. Again with quick couplers. If you need the EXACT fittings and numbers let me know and I'll look them up for you.....Dennis