Global Positioning Systems (GPS)

Polar Grit X, Rugged Multisport GPS Smart Watch, Ultra-Long Battery Life, Wrist-based Heart Rate, Military-Level Durability, Sleep and Recovery, Navigation, Trail Running, Mountain Biking ULTRALIGHT OUTDOOR WATCH WITH EXTREMELY LONG BATTERY LIFE: Up to 40 hours of training with GPS and optical heart rate measurement (up to 100 hours in energy saving mode), up to 7 days in watch mode with continuous heart rate measurement. At 64 g,... Polar Grit X, Rugged Multisport GPS Smart Watch, Ultra-Long Battery Life, Wrist-based Heart Rate, Military-Level Durability, Sleep and Recovery, Navigation, Trail Running, Mountain Biking