BullTronics MIB IV User Manual page 8

Bluetooth - Bluetooth Phone
The Bluetooth of the mobile phone needs to be connected to the car to use
the Bluetooth phone function.
1、Turn on the Bluetooth function of the mobile phone and the car device
separately, and set the phone to "Everyone is visible."
2. Search for the Bluetooth device in the mobile phone. After searching,
select and connect. At this time, you need to enter the pairing password,
which is usually: 0000. After the input is completed, the connection is
successful.