HR-50/B/N Optical Heart Rate Monitor and Activity Tracking Band Description GlobalSat HR-50 series support optical heart rate monitor and activity tracking functions as wearable personal belongings. It is adopted for people who exercise for broad kinds of outdoor sport, such as walking, jogging, running...... It can be also used to know and record your real-time heart rate without wireless heart rate belt. And it can monitor your daily actions such as steps, calories and sleep status. It is convenient for people who are in exercise and daily activities.