[Ian]’s theory is that this allows Casio to save on manufacturing costs by sharing one basic PCB between a variety of watches and enabling features via the jumper selection. With a little solder ...

The companion app from Casio is decent and allows you a way to control the watch without all those menus. So if you want to re-order the sports available or setup the data screens, for example ...

There's a new Casio G-Shock – and it's based on the oldest ... It was designed to offer something which the best watches of the time could not – reliability even in extreme environments.