Vivosmart HR smart activity tracker with Elevate wrist heart rate technology measures heart rate at the wrist 24/7. That gives you the freedom to work out with no additional heart rate strap needed. Using heart rate, v'vosmart HR provides calories burned information and quantifies the intensity of your fitness activities, providing better credit for your efforts. You can even use your v'vosmart HR as a heart rate strap on your wrist when paired with other compatible Garmin devices.