When you receive the watch or do not use the smartwatch for a long time, connect the charger correctly and charge the watch for 2 hours before using it. The above situation is caused by excessive discharge of the watch due to unused for a long time. For other questions, please contact us. 24/7 Heart Rate Monitor After exercise, you can check the data on the smart watchs or related app, such as exercise time, average heart rate, distance, steps, calories. 5 ATM waterproof Swimming Watch Waterproof smartwatch is an IP68 waterproof standard, you can wear it when you are washing hands and even wear it swim. Automatic Sleep Tracking This android watch can automatically 24-hour real-time monitor and analyze your sleep quality and shows with deep sleep, light sleep, and wake up time (only record the sleep lasting more than 3 hours).