Polar FS3 Heart Rate Monitor Watch Visual and audible alarm in target zone / Water resistant to 50 meters / Extra large digits Recording features - Exercise time (total) / Average heart rate of total exercises / Maximum heart rate Watch features - Time of day / Stopwatch / Date and Weekday indicator / Backlight Includes Wrist Unit with CR2025 battery, Transmitter with built-in lithium cell, and Elastic Strap to hold transmitter on chest.