a control unit for controlling devices or assemblies comprises a plurality of control elements located on a control surface . these control elements are provided with correspondingly assigned symbols for visually displaying the function of the respective control element and can be adjusted into at least two positions . in order to make reliable control easier , even under unfavorable light conditions , the control elements or an area directly adjoining them are provided with means for distinguishing the respective control element haptically . the control unit is suitable in particular for controlling a heating and / or air conditioning system in a motor vehicle .