Opel CD 70 Manual page 23

Introduction 21
An external source (e.g. hands-free
kit) can be connected to the
Infotainment system.
With External In the volume of an
external source can be set in addition
to the volume of the audio sources.
The external source is relayed
automatically by means of a control
signal from the connected unit.
AUX In:
With this setting, the sensitivity of the
Aux input can be adjusted to the
volume of the external unit.