Excerpt: I bought these headphones for running and biking. I chose them over the (slightly more expensive) other versions because I am planning on using them with a helmet on. I was worried that they wouldn't be as secure as the PMX 685is, but they are really secure. The adjustable brace on the earphone works really well, and I can wear them through miles of running with no issues. They also sound great for workout headphones, but I can hear my environment quite clearly.
Pros: Comfortable, Compact Design, Easy To Use, Great Sound Quality