Hygiene unit for compatible KWC self-closing thermostatic wall-mounted mixers for sanitary facilities and shower facilities, for carrying out automatic hygiene flushing and for saving statistical data. C-module including control electronics and 6 V lithium battery (CR-P2) as well as solenoid valve cartridge. Activated water hygiene flushing (30 seconds), fixed interval of 24 hours and saving of statistical data. With option for radio-controlled parameterisation, read-out of statistical data, realisation of predefined calendar functions as well as grouping of taps to perform predefined control functions via the necessary app. With polished chromium-plated brass housing adapter.