Better measure calorie burn, understand resting heart rate & more with 24/7 heart rate tracking and a battery life of up to 7 days (varies with use and other factors). Fit guide for small wrists (5.5 7.1 inches) and for large wrist (7.1 8.7 inches). Synchronizing requires Bluetooth LE and Internet connection. Windows 10 computers that do not have Bluetooth LE will need a wireless sync dongle in order to synchronize. Syncs with iOS 10 and later, Android 5.0 and later, and Windows 10 devices

Choose from 15 plus exercise modes like run, bike, swim, yoga, circuit training and more, set a goal, and get real-time stats during your workouts to see how you can keep getting better

Automatically record time spent in light, deep, and rem sleep stages, see Activity trends, health insights, and personalized guidance in one place with Fitbit today. Operating temperature is -10 to 45 C

Swim proof and water-resistant to 50 meters so you can track swims and wear in the shower. Also, connect to smartphone GPS for real-time pace and distance during outdoor runs and rides

Stay connected to your day with everyday apps for weather and more and get call, text, and smartphone app notifications on your wrist. Syncing range up to 6 meters
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