Water supply and distribution plants and structural parts thereof, flow rate controllers and flow limiters being parts of sanitary installations, namely, water taps, [ shower installations and heating systems; ] nozzles being parts of sanitary fittings, namely, aerating nozzles for water taps and showers; flow straighteners, namely, flow controlling flow straighteners and pressure compensation flow straighteners being parts of sanitary fittings for water taps and showers; showers, especially variable spray showers, [ massage showers, wall-fitted showers, ] and kitchen mixer taps, components and spare parts for showers and water taps, namely, flow regulating aerators, flow limiting aerators, pressure compensating aerators, flow regulating flow straighteners, flow limiting flow straighteners and pressure compensating aerators