Garmin has unveiled a sleep- and health-tracking band meant to be strapped to the upper arm. When worn overnight, the Index Sleep Monitor tracks sleep stages, heart rate and your breathing to create a “comprehensive view of overall fitness and recovery”. In the morning, you get a personalised sleep score.

The $169.99 device needs to be worn like a blood-pressure cuff, so that it can track breathing patterns and skin temperature, besides other metrics.

Being a device without a screen, Index Sleep Monitor is similar to the wrist-worn Whoop band. Unlike smart beds and mattresses like the Eight Sleep Pod and Sleep Number, the device is reasonably priced. And it doesn’t have any of the distractions of a smartwatch. The thermometer monitors skin temperature, offering insights about how your environment is affecting sleep while flagging possible illnesses. It can also offer women insights into menstrual cycles and past ovulation estimates. But Garmin says Index Sleep Monitor is not a medical device and is “not intended for use in the diagnosis or monitoring of any medical condition”.

More health-related metrics are available through the Garmin Connect mobile app, which has details about stress levels based on sleep patterns and a Body Battery measurement letting you know if you need more rest. Heart rate variability (HRV), which is a measure of the varying times between heartbeats, is also an important metric.

Garmin rivals Samsung and Apple continue to experiment with new form factors, like health-centric rings and earbuds. The expansion is an important milestone for Garmin, which also sells scales and blood-pressure monitors.