How to Enter Bluetooth Pairing Mode
Make sure that the headphones are off. From there, hold the power button for about 5 seconds until the LED indicator alternates between flashing RED & BLUE.
Note: If you are turning on the headphones for the first time, the headphones will automatically go into pairing mode (the LED will flash RED & BLUE.)
Now you should be able to find Avantree ANC032 in your device's Bluetooth menu.