ELECTROCARDIOGRAM* — The watch and heart rate monitor watch detects atrial fibrillation or normal heart rhythm in just 30 seconds via ECG.,SLEEP TRACKING — Sleep tracker delivers a Score based on light and deep sleep cycles, sleep duration & wake-ups.,HEART RATE TRACKING — Track heart rate continuously during workouts to optimize training, and monitor daily and overnight heart rate to help improve health over time.,WRIST-BASED OXIMETRY — Provides on demand oxygen saturation level (SpO2) in just 30 seconds,WATERPROOF watch - waterproof watch for swimming. Water resistance up to 50m.,24/7 ACTIVITY TRACKING — Dedicated workout metrics, Fitness Level via VO₂max estimation, connected GPS, elevation and step tracker. Great as a running watch.,DURABLE DESIGN — Combined heart rate and SpO2 sensor, 3 electrodes, an altimeter, a sapphire glass and a PMOLED screen featuring a rechargeable battery that lasts up to 30 days.