EL Backlight: (with Auto Light) An electro-luminescent panel causes the entire face to glow for easy reading. Auto Light: Automatically turns on the EL backlight when the watch is tilted towards your face for reading. Altitude Measurement: A built-in pressure sensor measures barometric pressure, which is converted to relative altitude. Barometric Pressure: Measurement A built-in pressure sensor measures barometric pressure, which is shown on the display. Underwater Depth Measurement: A built-in pressure sensor measures water pressure, which is converted to underwater depth. Temperature Measurement: A built-in temperature sensor measures the temperature. Reminder: A caution mark on the display reminds you of things you want to remember. Stopwatch: Accurate measurement of elapsed time with the touch of a button. The fraction indicates the unit of measurement, while the time figure indicates the maximum time measurement. Yacht Race Timer: Counts down from a start time specified by you. The value indicates the number of timers available, while the time figure indicates the maximum starting time. R indicates Auto Repeat, which automatically restarts timing at the end of each countdown. Daily Alarm and Hourly Time Signal: The daily alarm sounds each day at the time you set. The value indicates how many daily alarms are available. The hourly time signal causes the watch to beep every hour on the hour. Full Auto Calendar: Allowances are made automatically for months of different lengths, in case date corrections for leap years are required. 12/24-hour Timekeeping: Times can be displayed in either a 12-hour or 24-hour format. Anti-reverse Bezel: Mostly available in divers watches, this bezel is designed so it is impossible to rotate it in the wrong direction. Spherical Glass: The surface of the glass is rounded. Band: Resin Water Resistant: 100 meters, 300 feet.