AfterShokz Sportz M2 open ear headphones sit comfortably in front of the ear, utilizing patent pending bone conduction technology to deliver stereophonic sound through the listener's cheekbones to the inner ear, enabling anyone participating in an activity - jogging, biking, skateboarding, hiking, skiing - to make/take phone calls and stay connected to both what they are listening to and the outside world. Built-in rechargeable lithium ion batter...