Xiaomi Mi Band 1S with optical heart rate sensor, shows you heart rate with PPG, you can see the results more intuitively. Top-level Bluetooth chip and military gravity sensor ensure 10 days ultra-long standby time for a full charging. It has the ability to unlock your Xiaomi with proximity security. This means the device and Xiaomi smartphone will connect based on the proximity of the Mi Band. It will track your running and walking distance as well. The smart wristband will also track your sleeping metrics and will serve as an alarm clock. It supports waterproof IP67 level, so you can take it off and wash it if it is dirty.

• Measurement of heart rate
  

• 10-day standby power

• Fitness monitor and sleep tracker

• Sleep-cycle smart alarm

• Unlock your phone without a password (Only supports Xiaomi Mi4, Xiaomi Note, Xiaomi 4C, Xiaomi Mi3 with Android 4.4 MIUI)

• Call Reminder: The band will remind you through vibration and flashing light when you do not answer calls for some time

• Water resistant(IP67): You do not worry about taking it with you to the shower

Specification:

• Brand: Xiaomi 

• Bluetooth version: Bluetooth 4.0 

• Waterproof: YES 

• IP rating: IP67 

• Screen: NO 

• Battery type: Lithium polymer battery 

• Battery capacity: 45mAh 

• Standby time: About 10 days 

• Compatible OS: iOS, Android 

• Compatability: Android 4.4 / iOS 7.0 and above system 

• Alert type: Vibration
  

• Shape of the dial: Elliptical 

• Case material: Magnesium-aluminum alloy 

• Band material: TPSiV

• Dimension: 37 x 13.6 x 9.9mm

• Weight: 5.5g

• Functions: steps counting, alarm clock, sleep management, call reminder, measurement of heart rate, calories burned measuring, distance recording