Have ordered two of these "Avantalks" to a Bluetooth bridge between non-Bluetooth enabled devices (old stereo, portable CD player, MP3 player, radio - all with at least line-out / Line-in to jack base) manufacture and as I said, it works. The enclosed cable / adapter help you get started quickly. On the packaging you go initially linguistically "non-German" to, in the package but there is a manual in German. There, the basic things are explained to the pairing. This differs marginal depending on whether the Avantalk in RX mode (receiver / receiver) or TX mode (transceiver / transmitter) operates.
The quality, as far as I can judge, it is good. Binding the jack I can not confirm at my two Avantalks. Dropouts in the transmission there for longer distances in the apartment, yes, but in combination with, for example walls between. But honestly, I have not "full penetration" expected. Faith, on "open track" the 10 meter distance specified are certainly more realistic than with acoustic obstacle course between.
Super product in function, handling and processing. From me there's five star deluxe and a buy recommendation!