The Runalyzer&reg; Heart Rate Monitor for iPhone (included : key + chest strap + armband) Evaluate your real efforts. Calculate your calories and body fat mass loss in real time. Measure day after day the benefits of your workouts on your heart and your body. Optimize your workouts according to your abilities and your goals. Compatible with iPhone 3G/3GS/4/4S/iPad/iPod touch and several applications.