The Timex Ironman Solar 50-lap watch has all the classic features of the superb Ironman series and forgoes the need for a battery Unique design features an easy-to-use, push-button format and utilizes natures most plentiful power source-sunlight Normal room light triggers display activation almost instantaneously large format numerals are easy to read during training runs. Power level indicator displays amount of stored power available Sleep mode powers off display to save battery power. Training log stores workouts by date, including best lap, average lap and total segment time. Features 50-lap/split time memory recall, 100-hour chronograph with lap or split option and 99 interval repetition counter. Total Run chronograph format excludes rest periods for accurate times on long runs or bike rides. 24-hour countdown timer includes countdown stop and countdown repeat. Provides 3 programmable audible alarms with 5-minute back-up alarm and on/off hourly chime. INDIGLO Night-Light illuminates the display for easy use at night. Linked timers for speed workouts and walk/run marathons walk 1 min./run 8 min.. Tough resin case and top ring are water resistant down to 100m 330 ft.. Polyurethane strap offers flexibility for a seamless fit. Overstock.