A waterproof watch with wrist-based heart rate and integrated GPS, the Polar Ignite GPS heart rate monitor watch combines bioimpedance electrodes and optical sensors for precise heart rate accuracy. Fitspark™ training guide lets you choose from ready-made daily workouts Nightly Recharge™ analyzes heart rate variability, sleep and breathing rate to show how well you've recovered from the demands of the day Get the valued insight needed to get a good night's rest with Sleep Plus Stages™ sleep analysis Integrated GPS provides all your speed, distance and route tracking needs Compatible with popular 3rd-party services including MyFitnessPal, Strava, Apple Health Kit and Google Fit Running program makes it easy to develop a personal and adaptive training plan for your next event 24/7 monitoring tracks your daily activity, including steps, calories and sleep Connect via Bluetooth® Smart to the free online Flow mobile app and online web service This is the size M/L; fits wrist circumference 155–210mm (6.1–8.25 in.)