Make every beat count with Fitbit Charge 2™—a heart rate and fitness wristband that automatically tracks all-day activity, exercise and sleep, keeps you motivated with advanced fitness features and displays real-time stats. Charge 2 - Small wrist size - 140mm to 170mm Charge 2 features: Get PurePulse® continuous, automatic wrist-based heart rate tracking—all-day, during workouts and beyond—all without an uncomfortable chest strap. Use continuous heart rate to better measure calorie burn all day and help you stay on track toward weight goals. Maximize your workouts using simplified heart rate zones (Fat Burn, Cardio and Peak) to gauge exercise intensity and ensure you’re optimizing your effort for your goals Track all-day activity like steps, distance, calories burned, floors climbed and active minutes and Track resting heart rate to gauge how your cardiovascular health and fitness levels change over time Automatically track how long and how well you sleep and wake with a silent vibrating alarm Use multi-sport modes to track specific workouts (Run, Bike, Weights and more), see real-time exercise stats like heart rate and calories burned on display, and get post-workout summaries on display. Use Connected GPS during run mode to see real-time stats like pace and distance on your wrist (when your phone is nearby) and see a map of your route post-workout in the Fitbit app. Effortlessly and automatically record select activities like walks, runs, rides, treadmill, sports & aerobic workouts with SmartTrack™ automatic exercise recognition Get a snapshot of your cardio fitness in the Fitbit® app and follow your improvements over time. Find moments of calm throughout your day with guided breathing sessions that are personalized based on your heart rate. Stay connected with call, text and calendar notifications on display (when phone is nearby) Get friendly Reminders to Move that encourage you to stay active throughout the day.