Just learned this one recently. These are surprisingly good earphones; they surpass the audio quality of several of my other pairs of more expensive earbuds, as well as in-ear style phones. As I write this, the ET-2720 is new. These shoes are built ruged and have very good traction in trail conditions. I?ll update this if they wear out poorly. personally I wish i would have purchased the 8 to 9 size. So much in fact that when I returned home, where I have more of the original Beats Pro ear tips, I left the replacement tip on (no need to mess with it). It is great quality and holds a lot. I wear a 7 1/2 M shoe, no matter what. It would be nice if there were a variety of sizes in the package, but ultimately, they can still be used for both large and small items.