Casio needs no introduction when it comes to watches, and the F-91 series is arguably their most iconic (or infamous, thanks to its association with Bin Laden). Affordable and reliable, this watch is worn by world leaders and everyday people alike. It has everything you need in a simple watch and is built to last a lifetime.

I’ve owned my F-91W for about 16 years, and the battery is still going strong, though the light has dimmed, making it hard to read the display in dark environments. This minor flaw only highlights its durability—I’ve worn it every day for over a decade, even in the shower, and it’s still ticking.

The only issue I’ve encountered is the weak backlight, which struggles to illuminate the display in low-light conditions. However, there are modifications to improve this, such as adding a polarizing film to change the color or create a negative display effect. I considered trying this but never got around to it. Speaking of modifications, the F-91W is highly customizable. I replaced the standard rubber strap with a NATO strap I bought inexpensively from AliExpress. A NATO strap is easier to clean and more durable than the stock rubber band, which tends to dry out and break over time. I chose an olive drab strap, but there are many colors and striped patterns to choose from. Swapping straps is simple: cut off the rubber bands, pull the spring-loaded pins to remove them, and insert the new strap.

To verify if your F-91W is genuine, hold the bottom right button until "CASIO" appears on the display. Be aware that high-end counterfeits may mimic this feature. Another way to spot a fake is to tilt the watch backward—if the display shows "8888888," it’s counterfeit. A genuine F-91W’s display will remain unchanged. For absolute certainty, open the backplate to check the build quality and look for "Casio" written inside, often with details about the jewels. Why anyone would counterfeit a $12 watch is beyond me.

Overall, the F-91 series delivers exactly what you need: accurate timekeeping at an honest price. It’s waterproof, easily adjustable, and includes one alarm, a stopwatch, a calendar, and the ability to switch between 12- and 24-hour formats. No need for the fancy features of expensive or tactical watches—what more could you want for daily use?


Pros

1. Exceptional battery life
2. Lightweight design
3. 30-meter (100 feet) water resistance
4. Excellent value for money
5. Highly customizable

Cons

1. Weak backlight
2. Stock rubber straps dry out and break; upgrading to a NATO strap is recommended for long-term use

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