Last year, Casio introduced G-Shocks equipped with v4.0 Bluetooth, the first to feature two-way communication. Using the buttons on the G-Shock, you could control the volume level on an iPhone 5, for example. Now, for 2014, the G’mix Rotary Switch (shown), controls your volume with the crown instead. Pretty cool.
It will be available in October 2014 for $200.