How did you sleep? Find out with the Index Sleep Monitor. Comfortable, lightweight and worn on the upper arm, this sleep armband can capture sleep-tracking and recovery metrics — including sleep score, sleep stages and HRV status — so you can better understand how your body recovers each night (data presented is intended to be a close estimation of metrics tracked). Usingskin temperature, advanced women’s health tracking can provide more insight into your menstrual cycle, including better period predictions and past ovulation estimates (this feature is not intended to support conception, contraception or birth control and is not a medical device). If you wear a compatible Garmin smartwatch during the day, your data will seamlessly sync via the Garmin Connect app for more insight into your health and fitness. Plus, get up to 7 nights of battery life.