It has to be said that, like the Oakley Thump, these specs look a bit odd the first time you get them out of the box. This is partly because the arms are much chunkier than those of a normal pair of sunglass (they're around 8mm thick), but also because there are two earbuds hanging off the ends of these arms.
The arms have to be thicker because they house not just the battery that's used to power the internal electronics, but also the call and music control buttons. The right side is home to the three music controls (forward, back and play/stop), while the left hand side has the three call controls buttons (volume up, volume down and call answer/hang up). There's no on/off switch. Instead, to start up the headset you just pull the earbuds out from the rear of the sunglasses' arms.