【Sleep Monitor】Monitor your REM when you wear it to sleep. It will tracks your rapid eye movement to provide better sleep data. 【Blood Oxygen】Track your Blood Oxygen and Heart Rate through out the day for a better healthier exercise. 【Water Resistance】IP68 water resistance to use while doing various activities. 【Notifications】Receive and read text messages, social media notifications, calendar alerts, incoming and missed call alerts to never miss an important moment. (quick reply functions available for Androids) 【After-sales service】 Our smart watches provide one year after-sales service, our company headquarters is located in California, we have retailed in major supermarkets offline, if you have any problems you can always send us an email, we will contact you at the first time and solve any problems you encounter smart watch