Twist-on wire connectors are available in a variety of sizes and shapes. While their exterior covering is typically made from insulating plastic or ceramics, their means of connection is a tapered coiled metal insert, which threads onto the wires and holds them securely. When such a connector is twisted onto the stripped ends of wires, the wires are drawn into the connector’s metal insert and squeezed together inside it. Electrical continuity is maintained by both the direct twisted wire-to-wire contact and by contact with the metal insert.
