Blood-Oxygen Saturation Measurement: Test your SpO2 level the moment you start feeling unwell, getting a better understanding of your physical condition and keeping your health under control.24-Hour Heart Rate Monitoring: Covers heart rate zones and provides warnings when your resting heart rate is abnormally elevated, keeping you aware of the exercise effect and reducing exercise risks.The Amazfit GTR 2 supports in-depth sleep monitoring, which can more accurately determine the sleep stage, monitor the sleep breathing condition, and provide quality analysis and suggestions for improvement based on a night of sleep.Check to see where your personal stress level lies - from relaxed, normal, medium or high - anytime you feel pressured throughout the day, so you know when to relax and reduce it.Activate one of the 90 sports modes that you need and, after the exercise is over, the watch will produce a corresponding analytical report which is also viewable in the mobile app, to help you continuously improve your exercise plan.Mobile music playback is supported with the Amazfit GTR 2, for you to control the music on your smartphone through the watch via Bluetooth connection.The Amazfit GTR 2 includes a microphone and speaker to let you answer calls on your watch when it's inconvenient to pick up your mobile phone. Connect the GTR 2 to your mobile phone via Bluetooth to ensure that you no longer miss important calls.The Amazfit GTR 2 now has an offline voice control feature. You can perform voice operations on your watch without internet access so that you can have your watch do everything you wish without touching the screen.