Rotary switches, also known as band switches, are manual switches that change the on-off state of contacts by rotating the operating handle. They can achieve single-circuit on-off, multi-circuit switching, or gear adjustment. Common gears range from 2 to 12, supporting various contact forms such as single-pole single-throw (SPST), single-pole double-throw (SPDT), and double-pole double-throw (DPDT), which can meet different circuit switching needs. They are mainly used in radios, tape recorders, televisions, and various instruments and meters.