A: While the device is off, Press and hold the call button till the blue & red LED light starts blinking alternatively.
Scan for "ZEB-BH504" headset on your mobile and connect it. (Password - 0000, if prompted)
A: Yes. You can Play / Pause & Toggle between Next / Prev. track.
A: Pair the first device with ZEB-BH504 headset.
Once the connection is complete, turn OFF the Bluetooth in the first device.
Now turn ON the Bluetooth of the second device and pair it with the headset.
Once paired, simply turn ON the Bluetooth of the first device and it will automatically connect to the headset.
Thus two devices would be now connected to the headset.
A: +5V DC.