This is a whopper of a deal on a higher-end model that features GPS and GLONASS to measure pace, distance, speed and other metrics when running, biking and performing a variety of other activities. The Fenix 5X also features an optical heart-rate sensor, all-day fitness tracking (steps, calories burned, active minutes and sleep), and the ability to show notifications from an iPhone or Android phone.
In addition to a larger size (51mm in diameter), the Fenix 5X includes features not found in the other Fenix 5 models. It comes preloaded with topographic US maps, routable cycling maps for turn-by-turn navigation, and other features like Round Trip Run and Round Trip Ride, which can suggest routes based on how far you would like to run or ride. Another feature, called Around Me, allows users to see different points of interest, waypoints and other map objects within in their range.