Keep everything in check with the Polar H7 Bluetooth Smart Heart Rate Sensor. It provides live heart rate to compatible mobile training apps, including the Polar Beat, via low energy Bluetooth smart technology. The soft fabric chest strap seamlessly adapts to your body shape for premium comfort. Compatible with iPhone 4S, iPhone 5, iPod touch (5th generation), iPad (3rd & 4th generation), iPad mini, and iPod Nano (7th generation). Provides live, accurate heart rate to compatible mobile training apps. Uses Bluetooth smart technology. Compatible with Apple products. User replaceable battery. Does not provide heart rate to Polar heart rate monitors. 2 sizes available.