Heart Rate with and Without the Chest-Belt. Touch Activated Case. 20 Function. ECG Accurate. Intellitrack. Multiple HR Zone Programming. Enhanced Memory Recall. Fat-Burning Zone Locator. 50M Water Resistance. Duo combines the most advanced sensing technologies to offer one heart rate management system that works for every type of sport or fitness regimen. Continuous Heart Rate with Chest- Belt (Running, Biking, Training), Touch Activated HR without Chest-Belt (General Fitness). Intelli-Track Heart Rate Zone Display. Visually track your Heart Rate in and out of your target zone. Heart Rate Monitor: Continuous and On-Demand HR Monitor, Any Touch Buttonless Techonology, Intelli-track HR Zone Perimeter Display. Enhanced Memory Recall. Calorie-Burn Monitor. Fat-Burning Zone Locator. % of Maximum Heart Rate. HR Zone Audible Alarm. Lowest, Average and Highest Heart Rate of Total Exercise. Below, In and Above-Zone Exercise time. HR Recovery Time. Activity Level Selector. User Selected HR Zones. Additional Features: Digital Time, Date, and Alarm. Countdown Timer, Stopwatch and Lap Timer, Back Light, Water Resistance to 50m, 5 Year Warranty. Touch Activated Case: Lightly touch anywhere on the top and bottom of the water case to instantly display your heart rate.