ScanWatch 2 isn't just a snazzy smartwatch with health tracking – it's a medical-grade electrocardiogram. Its upgraded PPG heart rate sensor makes this even more accurate than the original. It can reliably detect potentially serious heart rate irregularities, including atrial fibrillation. And you can relax because you'll be notified in real-time, 24-7. And you'll sleep soundly too, with clinically validated SpO2 keeping a watchful eye. Throughout the night, sensors monitor your breathing for disturbances that could indicate apneic episodes. And then you'll wake up to a sleep score. Withing's latest trick is day and night temp tracking. Any big changes in body temperature and you'll know about it. That can help guide your workout recoveries or give you a heads-up if you're getting rundown by an illness.