Ava Fertility typically identifies 5 out of the 6 most fertile days per cycle.
https://www.avawomen.com/fertility
An FDA-cleared wearable bracelet worn overnight to identify a woman's fertile window by tracking physiological signals like skin temperature, resting pulse, heart rate variability, and breathing rate, helping users time intercourse to increase pregnancy chances without daily temperature-taking or urine tests. Worn while sleeping, it syncs data to an app, using machine learning to pinpoint fertile days, especially useful for those with regular cycles (24-35 days). "
Everything included + box, some paint wear on the buckle.