If only an aircraft radio is controlled, the active and the standby channel is displayed using very large letters. Additionally, station identifiers can be displayed. The rotary knobs control the volumes (active and standby channel), the rotary knob pushbutton toggles active and standby channel. The pushbuttons on the top of the display trigger commonly used functions such as channel selection (CHN), a nearest station list (NRST), or the “say again” function (SAGN, AIR COM only).