The "A100" series is a reproduction of Casio's first resin-cased model, the "F-100." Based on Casio's first resin-cased model, the "F-100," released in 1978, the band is made of metal and the case is plated.

The logo on the face, the function descriptions, and the side button colors reproduce the original F-100 colors when it was released. The design is also unique because it has function buttons on the front. The color is silver.