.25 gpm BLFC Button used in Fleck Valves to regulate the refill rate during Brine Refill.
Cross Reference Rainsoft PN 17954 ( Flow control washer 0.25 gpm )
And if your brine cam gear salt setting goes from 3 – 18 lbs. then you use 0.25 gpm BLFC
For a more information about the difference size BLFC buttons and how they match with difference Brine Cam salt Labels,