This Marathon stopwatch is easy to use and comes with an easy to understand instruction manual. It includes an alarm, a glow that is easy on the eyes and large digits for clear visibility. The alarm can easily be set by the push of a button and can be put on snooze for 5 minute intervals. The alarm repeats daily unless rescheduled. With an hourly chime feature, this stopwatch is great for staying on schedule. The split time button allows users to keep track of 2 athlete's recorded values at the same time. For extra efficient timing, this stopwatch has 1/100th second accuracy. The time and date are displayed large enough to not cause a strain on the eyes and a blue backlight was included for darker settings. Being lightweight it will not cause any strain to your neck when worn! Works great in the any indoor or outdoor setting. Water, dust and shock resistant makes this stopwatch long-lasting! The LCD screen will dim when battery needs replacing. 1 CR2032 battery is included.