Displays current heart rate zone readingsFeatures heart rate zone alert function: Heart Rate Monitor beeps and icon flashes when heart rate is below or above target training zoneTracks calories burnedStopwatch timer counts up to 29hr 59min 59sec with 1/100th second precision12/24-hour clock with alarm function and calendarEL backlight for easy viewing in lowlight conditionsWater resistant (up to 164 feet/50 meters) and shock resistant (up to 3 feet/1 meter)Requires one CR2032 batteries (included)