My repeated experience with sony products (walkman, couple of other headphones, camera) is surprise and excitement about how much attention designers dedicated to customer's value. These earphones are a rare example of u s e f u l innovation, e.g.

My standard ear bud earphones kept falling out when I was running, so wanted something that would stay put. Very pleased with these, great value. Before buying, read one review that said they were a little fiddly to fit, but had no problem with them. A nice comfortable and secure fit.

I bought these as the headphones I had with my phone just don't stay in my ears. These are great for the gym when I'm moving about. They stay in place as I hoped!

Its only for running. The sound quality is just average..sound quality is normal no extra bass like in other sony headphones. So purchase this if u need this only for sports activity.

They stick in my ears when I'm running but the sound quality isn't the best.

[...]. They constantly fall off my ears therefore causing a real lack in sound quality. I definitely wouldn't recommend these to anyone. $[...] wasted. I bought a Sony product on purpose, expecting quality.