Drain Line Flow Control ( DLFC ) Retainer For 5600 and 9000 Injector Drain Modules.
Includes the ultra thin o-ring, PN 15348 ( almost invisible ).
This retainer sits inside the 1/2" drain fitting connection on the Fleck 5600 and 9000 models.
It can be unscrewed using needle nose pliers to gain access to the DLFC Button behind it for cleaning or replacement.
The correct flow rate for the DLFC button is based on the tank diameter and application ( media in tank ).
CUNO ( Aqua Pure ) cross reference part number 55640-95
see more about Tank Diameter - How To Measure and Why It Matters