Circular Connector are a kind of electrical connectors

Electrical connector

An electrical connector is an electro-mechanical device for joining electrical circuits as an interface using a mechanical assembly. The connection may be temporary, as for portable equipment, require a tool for assembly and removal, or serve as a permanent electrical joint between two wires or...

, notably designed with a circular section.

History

Circular connectors sold must now comply with the MIL-C-5015

MIL-DTL-5015

MIL-DTL-5015, formerly known as is a standard for circular multi-pin electrical connectors used in harsh environmental conditions. Amphenol and are notable manufacturers of this type of connectors and In2Connect a notable distributor, and the connectors themselves are also sometimes called...

 standard. Circular connectors were first invented for aviation applications during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 and thereafter used for many industrial applications due to their versatility reliability and ease of supply.

Coupling

The coupling system may vary from the most common threaded coupling system, to the bayonet

Bayonet mount

A bayonet mount or bayonet connector is a fastening mechanism consisting of a male side with one or more pins, and a female receptor with matching L slots and spring to keep the two parts locked together....

and to special coupling system.