Fitbit Sense 2 - The smart watch that measures your heart rate, fitness and activity during the day and your sleep patterns through the night. 40+ training modes, Active Zone Minutes, resting heart rate and skin temperature, etc. With ECG app, Fitbit-Pay, built-in GPS and cEDA sensor to record and measure your stress levels. Comfortable, water-resistant design and with a battery life of about 6 days.