I did a lot of research before purchasing the Mighty Vibe and this device has made my 10km runs so much easier. This device is very small and clips onto your pants easily (hides under your shirt). It connects to my Powerbeats Pro (see below for steps to connect is successfully each time). The device has great battery life, high quality audio, sync's in a reasonable timeframe, is easy to charge (with the little usb adapter) and is great overall.
Highly recommend this device to runners looking for an iPod shuffle alternative. It is also good for walkers (listening to music or podcasts).
Powerbeats Pro steps (I had issues with connecting it unless I follow these steps every time) 1. Turn the device on (wait for a minute until the green light flashes) 2. Open your Powerbeats Pro case 3. Take the headphones out 4. Put them on and wait for it to connect 5. On the Mighty, press the play button