With the launch of its first watch in November 1974, Casio entered the wristwatch market at a time when the watch industry had just discovered digital technology. As a company with cutting-edge electronic technology developed for pocket calculators, Casio entered this field confident that it could develop timepieces that would lead the market. In developing its own wristwatches Casio began with the basic question, "What is a wristwatch?" Rather than simply making a digital version of the conventional mechanical watch, we thought that the ideal wristwatch should be something that shows all facets of time in a consistent way. Based on this, Casio was able to create a watch that displayed the precise time including the second, minute, hour, day, and month — not to mention a.m. or p.m., and the day of the week. It was the first watch in the world with a digital automatic calendar function that eliminated the need to reset the calendar due the variation in month length. Rather than using a conventional watch face and hands, a digital liquid crystal display was adopted to better show all the information. 

These watches feature replaceable batteries, which can be conveniently swapped out at your local watch repair store.