TECHNOLOGY: Solar charging capabilities allow you to charge while outdoors Up to 24 days of battery life in Smartwatch mode or 54 days while solar charging Up to 30 hours in GPS model or 38 hours while solar charging Track your adventures in more challenging environments with multiple global navigation satellite systems (GPS, GLONASS, and Galileo) Built-in 3 axis compass and barometric altimeter Smartphone connectivity allows you to see phone notifications right on your wrist USES: Track your heart rate, stress, sleep, and Pulse Ox Monitor how your body uses energy with Body Battery(TM) energy monitoring Gain a better understanding of your health and wellness with real time data and statistics Get more out of the sports you love with activity tracking for running, biking, strength, and more SPECIAL FEATURES: Water-rated up to 100 meters Constructed to U.S. military standard 810 for thermal, shock, and water resistance View how various settings and sensors impact battery life and make battery-extending changes on the fly