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 and 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