Manufacturer details checked
Casio
B640WMR-5A
- Manufacturer SKU
- B640WMR-5ADF
- Case dimensions (L×W×H)
- 38.9 × 35 × 9.4 mm
- Weight
- 55 g
- Case and bezel material
- Resin
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Manufacturer model details
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- Manufacturer SKU
- B640WMR-5ADF
- Case dimensions (L×W×H)
- 38.9 × 35 × 9.4 mm
- Weight
- 55 g
- Case and bezel material
- Resin
- Band
- Stainless Steel Mesh Band,Adjustable Clasp
- Water resistance
- 50-meter water resistance
- Power supply and battery life
- Approx. battery life: 3 years on CR2016
- Glass
- Resin Glass
- Surface treatment
- Rose gold ion plated band
- 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 unit: 1/100 second (for the first 60 minutes) 1 second (after 60 minutes) Measuring modes: Elapsed time, split time, 1st-2nd place times
- 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
- Alarm/hourly time signal
- Hourly time signal,Multi-function alarm
- Flash alert feature
- Flash alert Flashes with buzzer that sounds for alarms, hourly time signal
- Light
- LED backlight Afterglow
- Light color
- LED:Amber
- Calendar
- Full auto-calendar (to year 2039)
- Accuracy
- Accuracy: ±30 seconds per month
- Other features
- 12/24-hour format,Regular timekeeping: Hour, minute, second, pm, month, date, day
Checked 2026-10-02 · Regional scope: Casio international · Manufacturer specifications; individual watches may vary.
Original manufacturer wording is retained for source data without a reviewed translation.
Recorded discovery details.
Official discovery source
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Open official manufacturer page ↗Source record: sitemap-casio · Publication eligible: no.
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As an Amazon Associate I earn from qualifying purchases.
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As an Amazon Associate I earn from qualifying purchases.
Affiliate link: WatchesAtlas may earn a commission from qualifying purchases, at no extra cost to you.
As an Amazon Associate I earn from qualifying purchases.
Affiliate link: WatchesAtlas may earn a commission from qualifying purchases, at no extra cost to you.
As an Amazon Associate I earn from qualifying purchases.
These are discovery candidates, not verified alternatives or product variants.