Excellent low-cost solution if you want to listen to music from YouTube, Spotify, etc. on your car's audio system.
As long as your stereo has an AUX and USB output.
It has slightly low volume and a somewhat long AUX connection cable.
It also supports answering calls through the audio system...

While it initially connected on its own, lately it keeps disconnecting constantly. I connect my phone to the car

Amazing, connects directly and quickly with the Bluetooth headphones to any TV that doesn't have it, and that's the main reason I got it in the first place, it's worth more than its price

Very nice and simple solution. I don't like that it has somewhat low output level, even with the phone's volume at maximum.

Good because it is two in one! It has tx transmission and rx reception bluetooth with a switch. There is a silly thing in rx mode. When it goes into operation (i.e., in the car where you play music from your phone to the sound system) it has a very annoying sound that tells you "bluetooth is Operation."

It does its job. However, it sometimes gives me strange issues with the volume. This could be a problem related to audio format/drivers, so I'm mentioning it cautiously. Additionally, it's incredibly annoying that it vocalizes whether it is connected or not, and the volume of the voice is at 500% compared to normal

I revived an old hi-fi system to play music from my mobile (iOS). It connected easily as a receiver and the music plays just fine. I plugged the USB into the corresponding port and connected it to the "portable" port of the audio system with the 3.5mm cable.

I wanted it in order to connect it to the audio output with the jack of an older TV and listen through the BT headphones. It connected on its own with the first try and overall everything is good. It does its job perfectly.

You can use it as a TX (it has a switch to choose whether it will work as a TX or RX, where TX is to send a signal, while RX is to receive a signal, like a regular Bluetooth) and play on any Bluetooth speaker. You connect its input to the line out of the radio. Your Bluetooth speaker will detect it immediately and play flawlessly! It just needs an additional 5V power supply. Super gadget!

I have tried various similar Bluetooth devices in the past from Chinese stores, but this one works very well. It connects to the car's USB without any interference, recognizes the mobile phone, and automatically connects as soon as you start the engine. The microphone quality for calls is satisfactory.

For music, it is excellent and you don't lose much in terms of quality or volume compared to the regular 3.5mm jack. Overall, it meets the expectations of a Ugreen product - it is of good quality and works well, at a reasonable price.

However, the price at €17, when I bought it, is not the best. I believe that around €10, at most €12, would be a more representative price, considering that with €2-€3 you can buy a similar gadget that works decently for that price and does the job. The very cheap ones simply lack in microphone quality and produce a muffled sound if connected directly to the car instead of an external source. This particular device does not have such issues.

Connected to Samsung QLED TV in order to transfer sound to an amplifier from a 3.5mm jack to RCA and play through the speakers because the TV did not have the output.
The sound is good, clear, and has a minimal delay compared to the picture, which is around ms. Overall, it is an easy-to-use device that delivers on its promises.
I also connected it to my mobile phone and played music through the amplifier. The sound was satisfactory.
Personally, I am satisfied!

It does what it promises. I now make use of a mini system that I had at my country house and had it ready for disposal.

It does what it says in the best possible way. Very stable connection. No delay in startup (lip sync, etc.). Excellent sound quality (I don't have an expensive amplifier but I am very satisfied with my Pioneer and Wharhendale speakers! For the money it asks, I feel like I made the purchase of the century! It also has a transmitter that I didn't need to try somewhere. The only problem I may have encountered is that I couldn't connect it with the "plug" that came in the package, but with my own RCA cable. Finally, it can be connected to one device at a time.