The determination of your own energy level using the Body Battery shows you the best time for your activities and keeps you updated on all notifications and calls with the Smart Notifications feature. The vívosmart 4 is your ideal companion to support and enhance your active lifestyle. You can wear your fitness tracker 24/7: at night, it measures your blood oxygen saturation and shows you the progression of your sleep phases. During the day, it is also a great companion in the water thanks to its water resistance of up to 5 ATM. It continuously measures your heart rate directly at your wrist and informs you about your endurance performance and stress levels.