Casio Analog-Digital Dual Time Men's Watch, Water Resistant 50M with Alarm/Digital Stopwatch, Auto Calendar Casio Digital-Analog Casual Classic Watch with Resin Band with a Black Face 50M Water Resistant, Dual Time, with Hourly Time Signal 1/100 Second digital stopwatch, measuring capacity: 59'59.99", and elapsed time measuring mode Auto Calendar with 12/24 Hour Formats, and Accuracy: +/-30 seconds per month Approx. battery life: 3 years, Battery SR920W, Module 3321/5156