Once you have understood by the (really German) "Brukermanual" like the one-button operation of the device expires, the works! BT connection with tablet (for reception) or TV (for sending) without any problems.
Advantageously, I find the operating without power supply, but with built-in LiPo battery that is charged via USB cable within 2-3 hours.
Transmission occurs without interference in good quality (I expect miracles from BT not), within 8-10m - (not too thick) even with walls in between.
I can not say anything yet about the durability that remains to be seen.
Addendum: After about 1 1/2 years the unit still works einwandtfrei. Even the Accu still holds good by. For under 40, a good buy.