Not liking the cables that hang around, especially when they are on headphones, it is very annoying when working for example. I already had wireless headphones, but the two headphones were still connected by a cable between them. Now I wanted to go further with real headphones without any thread.
Content of the box and technical characteristics
- Replacement rubber earpieces
- The storage box (contains a battery + 2 earphones)
- Micro USB Charging Cable
- Starting instructions in English
The test
The box first allows to store them and carry them everywhere safely, and inside there is a loading dock of 700mAh which allows to recharge about 4 times the headphones. Each headphones as for them contain 50 mAh each. At the back of the dock there are 4 small dots that indicate the charge level of the 700mAh internal battery. On the top of the dock, there are two red dots that indicate that the headphones are being loaded inside. It is very convenient to know when the load is finished, because the red led then becomes blue. That's a good thought. At the bottom of the box, there are the two systems of pins charging the headphones, we put them just in the only way possible and it loads. On the other hand, positioning is not magnetized, but it is not necessary. In fact, shaking the box, nothing moves, there is no game after the box closed. A full charge allows to listen to music for 2:30, for me the time is variable but remains in this range, between 2:15 for the least good performance and 2:34 am for the best measure. So with the dock one can hold a whole day. 
Pairing is classic in Bluetooth 5 and is retro compatible with older standards. When first pairing is done, when I open the box the headphones automatically connect to the Smartphone (or any other Bluetooth device). When I close the doc the connection is stop and the headphones will reload. This system allows to simplify the headphones themselves that are small, the ignition is done simply by opening the box. So there is only one multifunction button per earpiece and they work with several current Player like YouTube etc… Quick press of the single multi-function button activates the pause/play functions while a long press allows you to switch to the next music. 
They also allow to pick up during a call, a small microphone is integrated with each earpiece, and both are active during a call (if one only wears it, it works whatever the earphone used). At the form and use level, they are rather classic, with a small additional appendage that allows to increase the stability once placed. They therefore do not only fit through the rubber in the ear and therefore have a better outfit than most of the headphones that hold only by the rubber part. When I tried to shake my head strongly, they did not fall off, the stability for me is conclusive and even better than some wired headphones. They are IPX4 certified, which means they are resistant to splashes and therefore to rain. The sound quality is good and clean, the bass a bit weak but it's normal for this type of product, and the sound is very clear. I'm pretty surprised for the sound quality for a wireless earphone at this price. For the comfort of listening in public transport or on the street, it's OK, the noise reduction is passive as on all the similar models I know. The sync between sound and image is perfect (using Bluetooth 5). I have not tested before the previous standards but this detail will not depend on your headphones but your equipment. 
Conclusion
Very good product and very good value for money. The only flaw, if you want nitpick, is the bass level but it's not a real problem either. To use, they are nice, lightweight, do not hurt even after several hours and above all, they hold well in place, I am very happy. Link: https://www.amazon.fr/Oreillette-Bluetooth-BlitzWolf-Écouteurs-Microphone/dp/B07HHPPHX2 (reduction of 4 euros right now, enjoy!) 