Note: This product is pre-sale product、 the price and parameter will be upgrade later.Parameter:Brand name: XiaomiModel: Miband 2Extremely narrow 8mm BatteryBattery capacity: 45mAhInput Current: 25mAInput voltage: DC 5.0VMetal surface material: Full magnesium - alloyBody shell: PolycarbonateADI military force sensorDialog's leading Bluetooth chipWristband Material: Dow Corning TPSIVWaterproof rating: IP67Adjustable wrist strap length: 157mm to 205mmSupports Android 4.4 or above、 Bluetooth V4.4 Android cell phones; Suitable for iPhone 4S\/5\/5C\/5S\/6\/6 plus with iOS 7.0 or aboveInternal configuration:Heart rate sensor: Optical heart rate sensorMeasuring method: photoelectric volume pulse wave plethysmography (PPG)Bluetooth chip: Dialog top Bluetooth chip (Bluetooth 4.0)Sensor: ADI military gravity sensorMain Features:Heart rate monitorCall reminderSports trackingSleep monitoringSilent alarmFree password to unlock the phone Package included: 1 X Miband 2 Smart Bracelet 1 X Charging Cable 1 X Manual