Timex Ironman T5G311 Midsize Bodylink System Heart Rate Monitor Watch Combines speed-and-distance data with heart rate monitor for serious runners Chest strap heart rate monitor provides target zones with alarm and time in zone Tracks your speed (real-time, average, and maximum), pace (real-time, average, and best), and overall distance 100-hour chronograph; 100-lap memory; 5 alarms Watch is water resistant to 50 meters (165 feet); up to 2-year battery life