20009X231 Final Rinse Piston CSA Can also be used to

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

Used on new-style Water Soft Isobar 1 softener valve

Please note that the male drain line flow control housing shown in #18 has been replaced with a female threaded version

Can be installed on Signature 1 valve body to upgrade to Signature 2 specs

20009X231 Final Rinse Piston CSA Can also be used toThe 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