Timex Mid-Size Ironman Road Trainer Digital HRM Watch & Flex Tech Chest Strap Flex-Tech digital sensor eliminates heart rate monitor cross-talk and electronic interference 50-Lap chronograph memory with average heart rate per lap Interval timer - each segment with its own target zone Target heart rate alert with time-in-zone data BPM or %-of-max heart rate display Indiglo Light-Up Watch Dial Indiglo Night-Light Target Heart Rate Zones including Time in Zone and Average Heart Rate for Workout and Lap Calories Burned and Percentage of Max Heart Display Water-resistant to 330 feet (100 M) Recovery Heart Rate Timer