Polar Equine H7 Heart Rate Sensor Belt Set Accurately measures your horse's heart rate during training using Bluetooth Smart technology Plastic electrodes are made from conductive material and ensure permanent contact with the horse's skin Includes H7 Bluetooth Smart and plastic heart rate electrode sensors Analyze your training details on Polar Beat and other compatible mobile training apps Compatible with the equine V800 and mobile training apps Accurately measures your horse's heart rate during training using Bluetooth Smart technology Plastic electrodes are made from conductive material and ensure permanent contact with the horse's skin Includes H7 Bluetooth Smart and plastic heart rate electrode sensors Analyze your training details on Polar Beat and other compatible mobile training apps Compatible with the equine V800 and mobile training apps Size M-XXL (660  20 mm / 953  20 mm) , Size XS-S (538  20 mm / 683  20 mm)