the closure element 120 is being moved by means of the drive unit 152 the signal generator 200 can be an optical signal generator which produces a light signal for example by means of an led in order to protect the signal generator 200 from water splashes provision is preferably made for the signal generator 200 to be arranged on the lower surface of the sink 100 then in the case of an optical signal generator 200 the thickness of the material in the region of the sink 100 located above the signal generator 200 is preferably made sufficiently thin as to let the light from the signal generator 200 penetrate through the sink 100 as an alternative or in addition thereto the signal generator 200 could also be in the form of an acoustic signal generator preferably the signal generator 200 is formed in such a way that it can produce different signals in dependence on the respective operative state of the movement mechanism 183 for example provision may be made for an acoustic signal generator 200 to produce the following signals in dependence on the respective operative state of the movement mechanism 183 soft beep whilst the closure element is being moved into the open position or into the closed position due to an actuation of the actuating device 165 by.