does the job perfectly
Allows you to make both headphones (which are not bluetooth) and an old-fashioned stereo system bluetooth (for use with a bluetooth speaker), thanks to an RX/tx switch. Works well, and the built-in battery lasts a very long time. One drawback is the ergonomics (stop, start and synchronisation), which would have been easier with a small display. But at this price, it's forgivable.