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 eneralBrandXiaomiBluetooth VersionBluetooth 4.0PeopleMale table,Female tableWaterproofYesWaterproof RatingIP67ColorsBlackScreenNoCompatible OSAndroid,IOSCompatabilityAndroid 4.4 / iOS 7.0 and above systemLanguageEnglishBatteryBattery TypeLithium polymer batteryBattery Capacity45mAhStandby timeAbout 10 daysSpecial FeaturesFunctionsAlarm Clock,Measurement of heart rate,Sleep management,Call reminder,Calories burned measuring,Steps counting,Distance recordingAlert typeVibrationDial and BandShape of the dialEllipticalCase materialMagnesium-aluminum alloyBand materialTPSiVWeight and SizeThe dial thickness0.99 cm / 0.39 inchesThe dial diameter1.36 x 3.7 cm / 0.54 x 1.46 inchesThe band width1.3 cm / 0.5 inchesWearable length15.7 - 20.5 cm / 6.18 - 8.07 inchesProduct weight0.014 kgPackage weight0.105 kgProduct size (L x W x H)22.50 x 1.36 x 0.99 cm / 8.86 x 0.54 x 0.39 inchesPackage size (L x W x H)10.00 x 10.00 x 3.50 cm / 3.94 x 3.94 x 1.38 inchesPackage ContentsPackage Contents1 x Xiaomi Mi Band 1S Smart Watch, 1 x Manual, 1 x Charger, 1 x BoxMy item don't work, my item is broken,what can i do ?Method 1: there is a Instructions, please read the Instructions again, and try to solve it.Method 2: if the item is broken, please send us photo, we will help you solve itMethod 3: if the item don't work, please send us videoI have not received my order. What can I do?Method 1: You can track your order with the tracking number given by the us, and we also tell your tracking webMethod 2: If you didn't receive your order and you Buyer Protection is about to end, please tell us as soon as possible, we will help you track and extend the protection date for you ( The tracking information will delay sometimes )Method 3: You can contact local post office to get help, the post office can't contact you sometimes, you need to go to pick your package up yourself ( Please check your personal information after you place an order, the information include name, address, zip code, Tel Number / phone number