and to a hot water line 13 which are routed to a water supply system that is not shown on the outlet side the mixer tap 9 is connected to a mixed water line 15 which carries the mixed water to the water outlet 3 the temperature and or volume of the mixed water is adjusted in a manner known per se through appropriate rotary and or tilting motions of the operating lever 17 of the mixer tap 9 horizontally opposite the mixer tap 9 another mounting adapter 19 is provided in which a control knob 21 as the second actuating element is rotatably mounted the mixed water line 15 connected to the mixer tap 9 is in plug in connection with a first connecting port 27 provided in a connecting piece 23 the connecting piece 23 is indicated in fig1 in a mounting adapter 25 vertically open toward the top of the fitting body 1 specifically at the inlet side of the water outlet 3 in addition a high temperature water line 29 is provided separately from the mixed water line 15 the high temperature water line 29 is inserted in a second connecting port 31 of the connecting piece 23 and is routed to a boiler 33 provided below the kitchen countertop in addition to the boiler 33 a refrigerating carbonating and or filtering unit 34 is provided in which fresh water can be filtered chilled and or carbonated the unit 34 is fluidically connected to the sanitary fitting by a supply line 35 and at its.