Main Features: 
Heart rate monitor: 1S with optical heart rate sensor, shows you heart rate with PPG, you can see the results more intuitively. 
• 10 days standby time: Top-level Bluetooth chip and military gravity sensor ensure 10 days ultra-long standby time for a full charging. 
• Call reminder: Mi Band 1S will tell you when a call comes, you never need to worry about missing any important calls. 
• Sports tracking: Track your sports, record steps, distance and calories, help you achieve your sports target. 
• Sleep monitoring: Let you know your deep sleep and shallow sleep, also APP will give you periodical evaluation, help you develop good living habits. 
• Silent alarm: Wake you up every morning, will not be late for work; Remind you with vibration, never worry about missing anything. 
• Free password to unlock the phone: Forget complex unlock password and gesture, simply raise your hand to close to phones, immediate and safe unlocking. 
• There is no alarm when the heart rate is beyond the normal range