The Casio F-91W-1DF provides digital timekeeping within a 21-gram resin housing. It utilizes the 593 module for ±30 seconds per month accuracy. A single CR2016 battery powers the unit for seven years.
Key Features
- 7-Year Battery Life: CR2016 lithium cell powers the module for 84 months. Battery swaps won't happen for years.
- 1/100-second Stopwatch: Measures elapsed time, split time, and two finish times. Tracks precise intervals during training.
- 3 Years Warranty: Official service coverage applies to the internal digital movement. Protects against long-term hardware failure.
- Resin Build: Synthetic resin forms the case and the 18mm strap. Resists corrosion from heavy sweat.
- LED Illumination: Side-mounted green light illuminates the digital display screen. Read the time in total darkness.
Frequently Asked Questions
Is Casio F-91W-1DF waterproof?
The watch carries a basic water resistance rating for light splashes or rain. Don't submerge it or wear it while swimming.
How to identify original Casio F-91W?
Holding the bottom-right button for three seconds prompts the screen to display "CASIO". Genuine units also feature high-contrast LCD digits and sharp back-plate stamps.