... rate monitor can help you train betterStoptatch,clock, alarm,calorie counterPolar 5Khz watch and chest strap compatibleWaterproof deepinto 50 metersDifference to Model HRM-2803 ... ,Exercise time display Heart rate warning : if current heart rate is over the heart rate range, warning by ringingDetect real time heart rate, max heart rate, min heart rate, average heart rateCalorie count ...