Pack of 30 monitors, each measures and displays Continuous heart rate, Average heart rate, Maximum heart rate, Target Zone, Out of zone visual alarm for high/low target zone, Audible alarm OFF mode, Time in/above/below target zone recall, Calories Burned, Time, Date and Exercise time on a large LCD display. ECG accurate. Monitors can interface with interactive exercise equipment. Recommended for ages 11 and up and meet the requirements of NASPE standards 3 and 4. Includes 30 monitors, 30 transmitters, 40 elastic straps and 1 aluminum storage case.