Casio was established in April 1946 by Tadao Kashio, an engineer specializing in fabrication technology. The company also became well known for the wide variety and innovation of its wristwatches. It is one of the early manufacturers of quartz crystal watches, both digital and analog. It also began selling calculator watches during this time. It was one of the first manufacturers of watches that could display the time in many different time zones and of watches with temperature, atmospheric-pressure, and altitude displays. Today, Casio is most commonly known for durable, large sized watches.