C81 - How to Connect Two Headphones to C81 Simultaneously

Pair the First Device 

Step 1: Get the C81 into Bluetooth Pairing Mode.
Press & Hold the MFB button on C81 until the LED indicator starts flashing WHITE&BLUE rapidly.

 
Step 2: Get the headphones into Bluetooth Pairing Mode as well.
Avantree Headphones/Speakers/Receivers: The LED Indicator on the headphone/speaker/receiver flashing RED & BLUE.

Step 3: Keep your Device close to C81, and give them a few seconds.
It takes a few seconds to connect.
Once successfully connected, the flashing on the C81 will turn SOLID BLUE.

Pair the Second Device 

Step 4: Repeat steps 1 through 3 again.