FunctionsBuilt-in heart rate sensor makes it easy to track your performance, Bluetooth and NFC pairing so you can connect to your devices wirelessly, StayHear+ Pulse tips provide a secure and stable fit for your most intense workouts, The Bose Connect app gives you real-time heart rate readings, and continually adds more functionality to your headphones, Works with popular fitness apps like MapMyRun, RunKeeper, Endomondo and Runtastic.