Supreme Precision for Endurance Athletes For endurance athletes who want precise coaching to perfect their training. ZoneOptimizer coaches you to train at the right intensity Sport profiles guarantee swift switch between different sports Improves performance with endurance training programs, downloadable from polarpersonaltrainer.com with the Polar DataLink Gives heart rate even in water with a comfortable hybrid transmitter Race Pace helps you cross the finish line in time Light (46g) and always ready for use with no need for charging Up to 8-11 months of battery life G5 GPS Sensor The extremely small G5 GPS sensor provides accurate speed and distance measurement for a range of outdoor sports. It is light and easy to wear in the armband pocket. After training you can see your route on a map with compatible software/web service. Ultralight (34 g) and small (39x64x12 mm) Measures speed/pace and distance Records accurate GPS positioning data Easy to wear in a soft and flexible armband (26 g) (provided) Rechargeable (20 hour life) via micro USB Whats in the box? Polar RCX5 BIKE Polar RCX5 training computer