All day, every day Conquer every hour of the day with advanced training features, 24/7 health and wellness monitoring, and up to 31 days of battery life in smartwatch mode. See it all on a stunning AMOLED display with a scratch-resistant sapphire lens. Key Features Long battery life Get up to 31 days in smartwatch mode or up to 58 hours in GPS mode. Built-in led flashlight Variable light intensities and a red safety light give you greater awareness while you train in the dark and can provide convenient illumination when you need it. Strobe mode can even match your running cadence. Hill Score This feature measures your capability for running uphill and evaluates your progress over time based on your VO2 max and training history. It measures your running strength on steep ascents and running endurance on long ascents and provides a score based on your performance over time. Endurance Score This feature measures your ability to sustain prolonged efforts and combines training data from all your athletic pursuits to help you understand how training impacts your overall endurance. This dynamic measurement uses your VO2 max, short-term/long-term training loads and other factors to gauge your fitness progress beyond just VO2 max. Rugged by design The resilient athletic design features a bright 1.3′′ scratch-resistant sapphire AMOLED display, responsive touchscreen, traditional buttons and 47mm fibre-reinforced polymer case with a titanium bezel and rear cover. The watch is tested to U.S. military standards for thermal, shock and water resistance. Knowledge is power Your health and training data should be easy to interpret and provide actionable insight. Begin each day with a customisable morning report, and see a daily summary of health and wellness information. Use the training readiness feature — which looks at a variety of different health metrics to help you maximise your training efficiency and recovery1 — to prevent burnout.