The Four-Way Switch, Model 9105, is a special type of DPDT switch that contains only four terminals instead of the normal six. The contacts for the missing pair of terminals are still there, but are internally jumpered to their diagonal opposites. With the toggle in one position, power is routed from each one of the input terminals to a corresponding output terminal. When the toggle is thrown to the other position the power is now routed from each one of the input terminals to the opposite output terminal.

A load can be controlled from three or more locations by placing one or more of these switches between two three-way switches. When used in this manner, it is called a four-way switch.

The four-way switch is also useful in motor reversing circuits where a change in line polarity or phase sequence is required