① Battery life data was measured by Huami Science and Sports laboratories using the factory default settings. 50 notifications were received and displayed every day, one alarm was vibrated for 5 seconds, and the touch key pressed 10 times. Every other operations was run for 2 minutes, manual measuring of heart rate was done 3 times, exercise for 1 hour per week (running function to detect real-time heart rate while the heart rate reminder was turned off), and moderate pairing was done on a daily basis with the Mi Fit APP. In actual use, the battery usage time is dependent on various factors such as settings, operation frequency and environmental factors, and may be different from the laboratory data results.

② Source of data: According to GB/T 30106-2013, it was tested by the National Quality Supervision and Inspection Center for Watches and Watches, report number: QT1803032, waterproof rating 5ATM (equivalent to a depth of 50 meters underwater). It can be worn while showering, swimming in the pool and lakes, but it is not suitable for saunas and diving.