20009X231 Final Rinse Piston CSA Piston assembly used on all

Piston assembly used on all residential DROP control valves

Used on new-style Water Soft Isobar 1 softener valve

0 gpm DLFC button

The Pioneer OX cartridge features ATOMUS MD1

Can also be used to upgrade a "TS" timeclock softener to a metered softener

20009X231 Final Rinse Piston CSA Piston assembly used on allThe Final Rinse Piston is only compatible with the following units: CSI Nitro, Nitro Pro, and WaterSoft Centuri filters manufactured after 6 1 2015 (or ones that have previously been upgraded to the final rinse piston). Any CSI Sidekick Any Water Soft Sidewindr Any Clearion Sidekick If your unit uses the Final Rinse Piston, it will have a red mark on the top, as shown in the photo. If your unit uses the standard piston (no red mark), its circuit board