In order to provide a building technology control element (1) having an actuating means (2), which has a label which can be changed in a convenient manner and requires a small amount of space, use is made of an interface (12) at least for transmitting data from an external input/output unit (8) that can be coupled to the interface (12) and at least one display element (3) whose display can be controlled using data which are transmitted via the interface (12), wherein a fluid (5) is provided between at least two transparent electrodes (4), said fluid containing mobile display means (3) which change their position in the fluid (5) on the basis of a voltage that is applied to the electrodes (4) in such a manner that a visible contrast in the sense of at least part of a character or at least part of a representation is provided at least on one of the two transparent electrodes (4).
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