In addition to its health- and sleep-tracking functions, the UP4 is equipped with a smart vibration alarm and can be used for American Express contactless payments in participating stores and venues. The UP4 is designed to be splash-resistant, so you can wear it in the rain or shower but not the pool or other bodies of water. The UP4's reachargeable battery is designed to last up to 7 days on a full charge and can be charged via the included USB cable. Activity Tracking The UP4 tracks your steps, exercise, and overall calories burned throughout the day. Knowing is the first step to get more active and stay motivated. Smart Coach Smart Coach gives you the motivation and insights you need to reach your goals, no matter where your day takes you. Plus, the more you use Smart Coach, the better its insights and tips become. Advanced Sleep The UP4 tracker uses sensors to automatically track your sleep stages: Wake, REM, Light, and Deep. Using this data, Smart Coach gives you suggestions to maximize your sleep and improve the quality of your days. Food Logging Log your meals and track calories with the UP barcode scanner, restaurant menu search, and food database. Smart Coach helps guide you to healthy habits and gives your meal a Food Score. Heart Health There's more to your heart health than beats per minute. The UP4's advanced bioimpedance sensors are able to automatically track your Resting Heart Rate and Passive Heart Rate to give you a more complete picture of your heart health.