20009X231 Final Rinse Piston Water Testing Kit Includes:

Kit Includes:

Can also be used to upgrade a system with a UVC-4 controller to the deluxe version

Note: We recommend installing a new seal & spacer kit anytime a piston is being replaced

used for chlorine reduction

20009X231 Final Rinse Piston Water Testing Kit Includes:The 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