Garmin's new Index Sleep Monitor fits around the arm to track breathing variations, sleep stages, heart rate variability, skin temperature and more.

Sleep tracking is nothing new in Garmin’s fitness watches, but the company’s latest wearable is a dedicated smart sleep band. The Index Sleep Monitor offers week-long battery life with continuous pulse ox tracking for monitoring your blood oxygen saturation while you sleep.

The Index Sleep Monitor is designed to strap to your upper arm so you can leave your smartwatch charging overnight.