@elizabethhunker http://womensrunning.competitor.... - this sensor is pretty sophisticated, sits on the core - which is where you learn the most about human motion, and works with every headphone you plug into or BT into your iPhone. Headphones with sensors are still quite rare, and they wouldn't sit on the pelvis, where we believe the sensor needs to be in order to make the most detailed observations.

@dshan You can find lots of reviews on the company's website - and here's a really detailed one - http://www.roadtrailrun.com/2016...