Green watch withIconic watch from Casio, the F-91W series has remained unchanged since 1991, and is a classic timepiece. The F-91WC gives an injection of colour to the design, with a colour blocked green rubber strap and plastic case with white writing. The case is water resistant, and inside is a digital quartz movement, featuring 1/100 second chronograph, alarm and date with annual calendar function, as well as backlight.