Casio AQ230A-1DM Basic Information Case size (L× W× H) 38.8 × 29.8 × 8.1 mm Weight 47 g Case and bezel material Resin / Chrome plated Band Stainless Steel Band Adjustable Clasp Water resistance Water Resistant Power supply and battery life Approx. battery life: 3 years on SR920W Exterior Glass Resin Glass Compatible band size 140 to 205 mm Watch Features World time Dual time Stopwatch 1/100-second stopwatch Measuring capacity: 59'59.99'' Measuring mode: Elapsed time Alarm/hourly time signal Daily alarm Hourly time signal Calendar Auto-calendar (28 days for February) Accuracy Accuracy: ±30 seconds per month Other features 12/24-hour format Regular timekeeping: Analog: 2 hands (hour, minute) Digital: Hour, minute, second, pm, month, date, day