Water supply installations and water distribution installations; air cleaning apparatus and installations, namely, air cleaning units; ionization apparatus for the treatment of air; air treatment apparatus, namely, air exchangers for cleaning and purifying air; showers; hand showers; toilets; toilets with bidet function; WC bowls, namely, toilet bowls; bath tubs and fitted liners therefor; urinals; bidets; toilet seats; toilet seats with bidet function; attachments with bidet function to be f...