Abstract: A knob adapted for mounting on a control shaft of a control device permits push-pull and rotary functions of the device to be selected. A rotatable skirt section through which the shaft extends covers unselected indicia on a display panel. A window on a portion of the skirt permits only a selected indicia to be seen. Upwardly extending arm members are attached to the skirt section, and are slidably received within channels of an overlying knob section. The overlying knob section is slidable upwardly and downwardly upon the upstanding arm members, but engages the arm members when the knob is rotated to facilitate rotational selection of the control functions. A spring biasing means is provided to maintain the skirt portion in a position adjacent the display panel to reduce the escape angle from under the skirt of light which may be provided within the display panel to illuminate the indicia, and to reduce paralax in viewing the selected indicia.