Move more: heart rate on the device via Bluetooth, more than 40 exercise modes, built-in GPS, activity division clock, daily preparation score, 24/7 heart rate, all-day activity tracking, aerobic fitness level, automatic exercise tracking, exercise intensity map and mobile reminder. Comfortable connection: Youtube music controller, Google Maps, Google Wallet, call, text and smartphone application notifications, bright color touch screen, customizable surface, timer and stopwatch. Health: Our most accurate heart rate, electrocardiogram and irregular heart rate notification, oxygen saturation (SpO2) monitoring, resting heart rate and high/low heart rate notification so far. 7 days of battery power, waterproof depth up to 50 meters. Stress management score, night sleep score, wrist mindfulness meeting, wisdom wake-up alarm, sleep and do not disturb mode. The size of the wristband is 140mm-180mm, and the additional size is 180mm-220mm. Also comes with a charger (compatible with Fitbit Charge 5, incompatible with other models).