SPECIAL Rainsoft Adapter coupling PN 51617 with o-rings ( large = 13287, smaller = 13305 ) but no clip ( RS19575 ).
This is used with Rainsoft In & Out head.
One Side ( the side that connects to the Tank Head ) is LARGER.
Sold Individually, so order 2 if you need a pair.
And again.. Clips sold Separately.
This NOT the same as Rainsoft 3/4" coupling adapter assembly, 17560 ( Fleck # 19228 ).
That adapter is the same size on both sides.