All black (double button) HEART RATE, SLEEP TRACKER AND ALARM ALARM: The fitness tracker allows you to automatically monitor the heart rate of your children every day in real time and know if they are sleeping well at night. Track sleep patterns of your children all night long via the app. The alarm allows children to wake up without disturbing them. Features Function: Activity Tracking (Pedometer, Distance, Calories), Heart Rate Monitoring, Sleep Monitoring, Multiple Sport Modes (Walking, Running, Hiking, Cycling, etc.), Message Notification (Calls, SMS, Facebook, etc.), Sedentary reminders, alarm reminders, looking for a mobile phone, Compatible & amp; Guarantee: Download and install the free app " VeryFitPro " by scanning the QR code on the box or search the IOS App Store. Applicable version: iOS 9.0 and above version, Andriod 5.0 and above system, support Bluetooth 5.0 (. 24 month warranty, lifetime technology service, 24 hour prompt response. If you have any questions or