This heart rate monitor provides live, accurate heart rate to compatible mobile training apps through Bluetooth Smart technology. Hook up the Polar H7 heart rate sensor to Polar Beat and get accurate heart rate to your mobile phone. Heart rate based training allows you to train at the right intensity, avoid under and overtraining and reach your goals faster. To use, attach the connector to the strap and wrap the strap around your chest. The heart rate sensor should be worn flat against the skin with the Polar logo in the upright position.