With these waterproof sports headphones, you can train optimally. The heart rate monitor helps you find your intensity, and motivating sounds ensure that you stay active. You can track your progress in the Philips Headphones app. Monitor your heart rate with the built-in heart rate monitor. A sensor in the earbud captures your heartbeat with the utmost precision. This way, you always know when to push harder and when to recover. Compatible with free fitness tracking apps.