• While you are connected through Bluetooth, you can switch between two phones.  Answering is made simple.
• Up to 5 Bluetooth devices can be connected to the head unit at the same time and you can enjoy audio streaming just by switching the devices with your friends or family.
• AOA (Android Open Accessory) protocol for USB allows audio streaming from most Android devices (Android 4.1 and Above).
• Smartphone application is prepared to control the head unit via Bluetooth like a wireless remote control.

If I'm out of KDC-X501, I will send out newer KDC-X502