Very good headphones. I use them only to listen to music via my phone, at night in bed. The battery life is very satisfactory. They connect immediately and there are no disconnections. I can't say anything about calls and I haven't used them simultaneously to observe if they sync well. If I use them differently, I will come back.

Update:
After 4 months, they broke. Specifically, while they appear to be fully charged, after 10 minutes of use, their battery is empty.

3 stars, or should I say 2. The sound is excellent when listening to music or watching videos. The battery is very good, as well as the case, which may need to be charged once every 15 days depending on my usage. However, what is terrible is their connectivity. It loses signal easily, even if I just have my phone in my jeans pocket! Even if I have my phone charging in a room and the headphones in my ears in a straight line, it loses signal. Honestly, I have never experienced anything like this before. Just for this reason, 3 stars.

For its price, it is very good. I tried it for music and speech on a mobile phone where the music sounds very good but I would like more volume, in speech it did not satisfy me at all. However, in mp3 it has more volume and sounds great. In conclusion, it is very good for music. They also fit very well for sports and the battery is satisfactory. They also fit very well for sports and its battery is satisfactory.

The headphones have very good sound with decent bass. However, the microphone is terrible, so they are not suitable for calls.

The headphones are excellent for their price, they fit perfectly, they have good sound which I did not expect for such cheap headphones, the battery is fine, I think 4 hours are enough and since it comes with a case with an additional 20 hours, they are worth it. My only complaint is that the sound from the microphone is bad, but only when there is a lot of noise. If you are somewhere in a room, there will be no problem, it's fine. I constantly talk and ask the kids if they can hear me well, and they say that I sound fine. I RECOMMEND THEM TO YOU.