Your watch is compatible with the HRM-Pro™ series accessory. The HRM-Pro series accessory is a chest heart rate monitor that you can pair with compatible devices using ANT‍+^® and Bluetooth^® technology. You can wear the heart rate monitor to record heart rate data and receive real-time feedback on your running form (Running Dynamics). The heart rate monitor's activity tracking feature records your step count, calories, intensity minutes, and all-day heart rate. You must pair the heart rate monitor with your watch to view your heart rate data. If your MARQ^® watch was packaged with the HRM-Pro series accessory, the devices are already paired. See the instructions for your HRM-Pro series accessory for more information.