The Regeneration Piston replaces the rejuvenating chlorine residual cartridge in the Clack WS1 Water Softener. This part is commonly used as a regeneration recovery or recovery booster recovery to fully restore the Regeneration cartridge's performance after fluctuations in production runs.

Used with Clack's V3174 Valve, this part can be used as a non-replacement regeneration cartridge for time-sensitive concerns such as needing to filter water very quickly or added pressure for certain water softeners.