Straight from the Casio Vintage Collection comes a timepiece that never goes out of style. The B640 combines style with features Casio is known for such as an EL backlight and a 1/100th second stopwatch. This timepiece is the perfect complement to any outfit. 50m water resistant LED backlight 1/100-second stopwatch Measuring capacity: 59'59.99" Measuring modes: Elapsed time, split time, 1st-2nd place times Daily alarm Hourly time signal Auto-calendar (auto calendar set at 28 days for February) 12/24-hour format Regular timekeeping Hour, minute, second, pm, date, day Accuracy: 30 seconds per month Approx. battery life: 7 years on CR2016 Module: 3454