This standard specifies the use of insulated closed-end connectors (hereinafter referred to as lightning wires) for interconnecting stranded annealed copper wires or single vinyl-coated electric wires (hereinafter referred to as lightning wires) used primarily for the internal wiring of household electrical equipment. This specification specifies connectors that are crimped onto the insulator using a connecting tool (hereinafter referred to as the tool) specified by the manufacturer of the connector.