The Lief is a clinical-grade ECG device that continuously measures heart rate and heart rate variability (HRV). Over time, the Lief will adapt to your body to represent your heart data to you in a meaningful way, and use vibration feedback to alert you when your HRV is relatively low.

The Lief uses reusable ECG stickers that snap into the patch and stick to your body in order to accurately capture your heart data. These stickers can be replaced every 2-5 days to maintain their adhesive properties.