As the name denotes, rotary switches are activated by rotating a knob. They are generally needed when the number of circuits that need to be changed simultaneously exceeds the capacity of a toggle or slide switch. Rotary (Multi-way) Switches have many conducting positions. They may have several poles (contact sets). They are available with a range of contact arrangements from 1-pole 12-way to 4-pole 3-way.For different variants of the rotary switch, the number of "ways" (switch positions) are reduced with a different "stop" under the fixing nut, limiting the movement where there are more poles to be served.