Comfort is the key when training. That is why Polar created the Polar WearLink®+ transmitter belt. It not only measures your heart rate but also seamlessly adapts to your body shapes so you feel as if it is not even there. The transmitter consists of an electrode strap and a connector and with its new side-clip mechanism, it is just as quick to put on as it is to take off. User replaceable battery. Removable and machine washable textile strap.