Better measure calorie burn, understand resting heart rate & more with 24/7 heart rate tracking and a battery life up to 7 days. Choose from 15 plus exercise models, like run, bike, swim, yoga, circuit training and more, set a goal, and get real time starts 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, heart insights, and personalized guidance in one place with Fitbit today. Swim proof and water resistant to 50 meters so you can track swims and wear in the shower. Radio transceiver; Bluetooth 4.0 Syncing range up to 6 meters.