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. Details Case Size (L x W x H): 38.9 x 35 x 9.4 mm Weight: 49g Case and Bezel Material: Resin Band: Adjustable Clamp, Stainless Steel Band Water Resistance: 50-Metre Water Resistance Power Supply: Approx. Battery Life - 3 Years on CR2016 Exterior Glass: Resin Glass Surface Treatment: Partial Ion Plated Watch Features Stopwatch: 1/100-Second Stopwatch, Measuring Capacity - 00'00"00 - 59'59.99" (For the first 60 minutes) 1:00'00 - 23:59'59 (After 60 minutes), Measuring Modes - Elapsed Time, Split Time, 1st-2nd Place Times, Measuring Unit: 1/100 second (for the first 60 minutes), 1 second (after 60 minutes) Alarm / Hourly Time Signal: Hourly Time Signal, Multi-fuction Alarm Light: LED Backlight, Afterglow Light Colour: LED - Amber Calendar: Full Auto Calendar (To Year 2039) Accuracy: +- 30 Seconds Per Month Timer: Countdown Timer, Measuring Unit - 1 Second, Countdown Range - 24 Hours, Countdown Start Time Setting Range - 1 Second to 24 Hours (1-Second increments, 1-minute increments and 1-hour increments), Other - Auto-Repeat Flash Alert Feature: Flash Alert, Flashes with buzzer that sounds for alarms, hourly time signal Other Features: 12/24-Hour Format, Regular Timekeeping, Digital - Hour, Minute, Second, PM, Date, Day