90 days of sensors included.
Two small sensors monitor your sleep from moment to moment.
They detect your sleep stages, enabling SmartSleep to deliver soft tones at the right time in order to enhance slow wave activity*, thus improve your sleep.
An adhesive behind-the-ear sensor snaps into the headband and has to be replaced after 3 uses.
* sensing accuracy and product performance is lower in people over age 50 due to a natural reduction in slow wave amplitude