Brine Stem and Seat for 1600 Assembly 3/8 = Part # 12552 ( stem ) and # 12626 ( seat ) together as one piece.
Parts # 17 and # 18 in brine valve assembly diagram.
This part is used in the assembly 60029 ( 1600 brine valve assembly "short stem" )
, and common for residential Fleck Valves, such as the 1500, 2500, 2510, and 2700.
This part is what usually wears out, and replacing it, while not "easy", can save you the cost of purchasing a complete new assembly ( 60029 ).
Our recommendation is to replace the Entire Assembly ( 60029 ), but we offer this for those who like to "rebuild" when possible as a way of saving money.