Shock Resistant 200 Meter Water Resistant EL Backlight with Afterglow Measuring mode: Elapsed time, split time, 1st-2nd place times Multi-function alarm Hourly time signal Full auto-calendar (pre-programmed until the year 2039) 12/24 hour formats Accuracy: +/- 15 seconds per month Battery CR2016 Approx. battery life: 2 years Module 1289/3230