How did you sleep? Find out with the Index Sleep Monitor. The comfortable, lightweight sleep bracelet worn on the upper arm can analyse the quality of your sleep and record your recovery values. Better understand how your body recovers each night thanks to functions such as Sleep Score, Sleep Phases and HRV Status (the data presented is intended to be an accurate estimate of the values recorded). Based on body temperature, the Women's Health function can provide more insight into the menstrual cycle, including better period prediction and estimates of past ovulations.(this function is not intended to aid conception, contraception or birth control and is not a medical device). The battery life even lasts up to 7 nights. If you wear a compatible Garmin smartwatch during the day, your data will be seamlessly synchronised via the Garmin Connect app to complete your health and fitness information.