Piston 3900 Lower Standard, No Hard Water By Pass allowed during regeneration process with this version of the Main ( Lower ) Piston Assembly.
PN 60107-10 has black
Cross reference = 312053 ( part of Kit 702157 ), FL60107-10, FLK60107-10,FP6010710
IF you need No Hard Water By Pass ( NHWBP ), then this is the one to order.
But if you have a white
end cap, that would indicate you need HWBP, 60107-00
Don't confuse the two different Lower Piston Assemblies.