after 8 months of daily use, the battery swelled. I tried to replace it by soldering but it has very thin wires and I couldn't manage it.

While it says that you can connect the 2 devices to the central unit and talk between them, this does not happen. It does not clarify that it only connects to a mobile phone, and if you want to communicate with the other person, you have to call them to talk on the road. This is not called intercom; it is called hands-free. Why would you buy something like this when you can just use a hands-free device? I wasted my money. I thought it was Chinese and that I could talk to my passenger. I didn't want long distances, etc. Anyone who wants hands-free is fine

If you are looking for a single helmet intercom that is value for money, this is a very good solution. It has very good performance in sound-music and phone for its price always. It doesn't bother if you end it and generally it is okay.
However, I should explain to those who have no prior experience... almost all intercoms after 100 and depending on the protection your two-wheeler has, stop being heard due to wind noise.
I gave it 3 stars because very quickly after I got it, the big button when pressed didn't always respond and I had to insist. However, it works perfectly even today

For its price, the communication is great. I use it on a jet helmet and I can hear perfectly and be heard perfectly as well. Obviously, you can't expect much from it, but for relaxed city rides, it's worth it if you don't want to spend a lot. It hasn't been exposed to rain yet, but it will (delivery person), and I will come back for updates.

Well, I got the BT 12 today at noon, I put it on my helmet which opens up and the headphones fit very well inside. The sound is thick and when someone calls, it is very loud and clear, and the same goes for when others hear me. This is the first time I write a good comment, whoever buys it should check their helmet to have depth on the side and it will be perfect. The intercom is amazing, I got it for only 19.34 euros

Used for work (courier and delivery). The positive aspect is its very low price. With a jet-type helmet, I had no problem being heard. It changes language without me understanding, resulting in it speaking Chinese to me, which is not a major issue. It requires attention because the headphones are very thick, so if the helmet does not have a provision for communication or a deep ear cavity, it cannot be used (I have a second jet-type helmet as well as a closed-type one, and I cannot wear it because my ears do not fit). Also, the charging cable hangs permanently and needs to be stored inside the helmet

One of the worst intercoms. It's good that it doesn't fit in my helmet, I use it for work (delivery) they can't hear me, I can't hear them, they hear their voice twice (when they call me) and when it's connected, instead of recording voice from the headset, it's recorded from my phone (messenger, Viber)... bad... very bad!!! Stay away!!!

Value for money 100%!! The sound and microphone are relatively good, it is very easy to install, and the battery lasts about 5-6 days with daily use. The only downside is that it speaks Chinese :P

I bought it because I saw good reviews. It doesn't fit my helmet properly. No matter how I tried to position it, I couldn't put the helmet on.

As a device, it works great, with very good sound and a good microphone. The battery lasts for a week with an average of 1 hour of usage per day. Easy to set up, with the only major drawback being that the headphones are bulky and tight on the head, at least with my helmet!

Very good sound & microphone, great battery life, it has endured two rain showers and so far no issues!