Pair CK11 to cellphone, pls make sure you follow this step by step:
1. Go to your phone Bluetooth list and unpair all bluetooth items.
2. Turn off phone bluetooth.
3. Switch ON the carkit.
4. Press and hold the volume button until the indicator flashes blue and red.
5. Turn on Phone Bluetooth function again and start searching for devices.
6. Found Avantree CK11 and connect.