The vivoactive 4S Smartwatch from Garmin provides you with a full-color, customizable, digital Garmin Chroma display, and built-in technology for all-day fitness and health tracking. The vivoactive 4S Pulse Ox sensor and wrist-based heart rate monitor can help gauge how hard you work out, if you have an elevated heart rate at rest, and how well your body absorbs oxygen during the day and while you sleep.