I purchased this for Bose Wave Music System IV so that I could wirelessly stream music, movie sound, etc. from smartphone, tablet, laptop, or other Bluetooth device. Setup was easy. All I had to do was plug it into the Bose Link port. Since this external adapter can only pair one Bluetooth device at a time, I had to turn the Bose on, then press AUX to cycle it to Bluetooth.

https://www.amazon.com/Bose-Wave-Bluetooth-Music-Adapter/dp/B007ZG03DG