Water resistant.Sleep-cycle smart alarm.Fitness monitor & sleep tracker. It can connect with your android 4.4 mobile phone(support connect the system with android 4.4 or more high), the Battery can support 30 days. You can view real-time physical activity through mobile applications, monitoring the effect of walking and running, you can identify more sport through the clouds.Xiaomi bracelet can automatically determine whether to sleep, deep sleep and light were recorded and summarized sleep time to help users monitor their sleep quality.