I was concerned that they would not be able to go in, but they did so without any issues in both ears. In my situation, it is not crucial (it is better to regulate what is occurring around than to entirely block it), but you won't walk like that.
Pros
Indoors, on a quiet street - it's better, in fact, the tracks sound with nuances that I hadn't catch previously; nevertheless, in a city on a busy street, in transit - it's worse. Beautiful, original, and tactilely delightful are some of the words that describe the application and control.
Cons
If you simply put it in (as in advertising), there is a possibility of it falling out. My interlocutors can hear me either in an empty room at a large distance from the microphone, or with a crash, loss of sound, on the contrary, I can hear it well. If you just put it in, there is a chance of it falling out.