150 Operating system Operating system CD radio overview Audio systems Function : Control knob RPress: Switches on/off RTurn: Sets the volume Changes settings in menus ; ´ Switches folders in MP3 and USB mode = w RPress briefly: Accepts a call RPress and hold: Activates Bluetooth® Starts Bluetooth® search Starts Bluetooth® pairing (pairing/external) ? Microphone for making calls via Bluetooth®