Tracks your speed, distance and route using the latest GPS technology (SiRFstar IV) * Slim and lightweight (58g) design with rechargeable battery and supersized digital display * Unique Polar Smart Coaching features such as Running Index and Training Benefit analyze your run and guide your training to the next level (heart rate sensor included) * Includes new ?Back to Start? GPS feature that directs you back to your starting point in the shortest distance possible. * Compatible with optional running and cycling sensors as well as polarpersonaltrainer.com, our free online training diary that allows you to share your training with friends