Polar - H7 Bluetooth Smart Heart Rate Sensor - Black
Keep track of your progress during workouts with this Polar H7 heart rate sensor that features Bluetooth capability, so you can send readings to Bluetooth-compatible devices. The included chest strap adapts to your body shape for comfortable wearing.
Does it count calories through the app?
I use it with endomondo app and works perfect. But I don't Think the caloríes count depends on the heart rate. The app gives me the work zones, wich is better info that the calories Burned.