The Casio F-91WM-3ACF is a modern twist on the classic F-91W series, featuring a distinctive metallic green resin case that adds a contemporary flair to its timeless design. This watch maintains the lightweight and comfortable fit characteristic of the series, making it suitable for daily wear. Equipped with an LED backlight, the F-91WM-3ACF ensures clear visibility of the digital display in various lighting conditions. Its compact dimensions, measuring 38.2 × 35.2 × 8.5 mm and weighing approximately 21 grams, make it an unobtrusive accessory on the wrist. The watch offers essential functions such as a 1/100-second stopwatch, daily alarm, hourly time signal, and an auto-calendar pre-programmed until the year 2099. Powered by a CR2016 battery, it boasts an impressive 7-year battery life, reducing the need for frequent replacements. With water resistance designed for everyday use, the F-91WM-3ACF can withstand minor splashes and brief immersions in water.