Main functions: medical grade ECG measurement, automatic infrared blood oxygen measurement, sleep apnea monitoring (snoring monitoring), HRV Lorentz scatter plot, precise and scientific sleep monitoring, respiratory training, heart rate monitoring, 10 exercise modes, female menstrual ovulation reminder, body temperature measurement, step counting, calorie, distance measurement, alarm clock, information reminder to turn the wrist to light up, remote photography, incoming and outgoing reminder to