I bought these headphones on 29.11.23 on Alza for 1890, - CZK. Basically identical headphones, Sennheiser HD 4.40 BT (which had only a jack input, which I never used), I bought before 7.4.19 in Datart for 2590, - CZK. Since both headphones are almost identical in design and technical parameters, I evaluate rather the experience with the previous ones. These are Bluetooth headphones of, let's say, medium class (18-22000 Hz), the sound quality corresponds to that. Such a middle class, they do not disappoint, nor completely delight, certainly not enough for audiophile gourmets or professionals. Bluetooth pairing with my phone (formerly Sony, now Zenfone) is a breeze. If you set the bridge between the two headphones sensibly, they won't push even after many hours. They hug my rather larger ears quite well, they are earbuds, so they don't go completely around the ears. I'm not too disturbed by anything or disturb others, I listen at home or on the terrace, mostly rock. I don't wear them on the street or for sports, so I don't need the more modern special ambient noise cancellers like e.g. ANC, which can do (according to reviews, I don't own one myself) sometimes quite unpleasant things and make the headphones unnecessarily expensive (that's why I stick to this, now slightly outdated type). I downloaded the Sennheiser Smart Control app to my phone. It offers mainly the possibility to adjust the sound using only a rather primitive three-band equalizer. I listen to music via Spotify or Windows Media Player, both of which have their own multi-band equalizers, so their settings are more detailed and the Sennheiser surround is probably not necessary. I also have the feeling that the app slows down the mobile/phone pairing significantly, I'll probably uninstall it soon. Why did I actually buy the same headphones after 4+ years? After 4 years with the previous ones, the leatherette padding started to crumble (see photo), so listening always betrayed its pieces stuck on the ears, although everything else worked and I was basically satisfied with the headphones. Philips and Sony headphones have done the same to me before and for a similar period of time - the padding and its similar (in)quality in all brands is simply the main limiting factor in the liveliness of earbuds. Compared to headphones of similar frequency range and sound quality, the Sennheiser 2 headphones evaluated have advantages: they're a little cheaper and they're foldable.