As a backup bluetooth pair for my main ones ( bose noise cancelling / bose sport ). I wear these as I work and find they do a great job of isolating ambient noise... they are not noise cancelling per se but very good for noise insulating. I can wear them as I run air con in background in one of the rooms I use as an office.
Secondly, while I was doing a detox, I wanted to find a way to listen to podcasts / training lessons while I was in the spa... so this time could be useful. They are just great for things like this... for example, you can wear them in shower and they just work well. Audio quality for water sealed ear tips isn't amazing but its more than adequate - and I'm fussy.
I haven't used them for swimming or totally under water - but they are fine in shower as much as office. I find them to be comfortable and like that they have built in mp3 player. As bluetooth headphones, they are decent too.