Crafted for comfort and durability, this generic replacement wristwatch strap is an ideal choice for your Casio F91W. The sleek black silicone/rubber material provides a smooth fit and easy maintenance, while the two-piece design ensures a secure and adjustable fit for any wrist size. Precision-engineered to match the 18mm strap width of your Casio F91W, this unbranded strap maintains the original look and feel of your digital display watch. A straightforward replacement or upgrade, it offers a functional and stylish solution to refresh your timepiece's appearance.